Simon Whysall

Partner and Principal

Simon Whysall, 21 years’ experience in private practice, is the Principal of Altor Employment Solicitors and an Accredited Employment and Workplace Mediator.

Rated in Band 1 by the Legal 500 and Chambers and Partners: Simon Whysall stands out as a leading employment adviser…. thanks to his “prompt responses, positive client relationships,”​ and, “detailed approach to any issue raised.”​ One source offered extensive praise for his wide-ranging work: “He is very knowledgeable, he deals with issues thoroughly, and he keeps a close eye on things to ensure the best result for us. Good, commercial advice.”

Simon has always practised as a specialist employment solicitor. He was a Partner and the Head of the Employment and Benefits practice in the Milton Keynes office of one of the largest law firms in the world for 10 years from April 2006 and before that he practised in two leading London based law firms.

Simon advises on all aspects of employment law and has particular expertise on employment litigation in the Employment Tribunal and High Court, restructures, business-wide changes to employee contracts, TUPE, collective consultation issues, the employment aspects of outsourcing projects and corporate transactions, PFI/PPP deals and data protection.

Simon regularly advises on executive exits and settlement negotiations and his work often includes a pan-European/international element. He has a close network of employment lawyers in other countries that he has worked with on international assignments over many years.

Simon has particular and extensive experience of advising on employment law issues in the transport, telecommunications, retail, education, media and financial services sectors. Simon has led and been responsible for the employment work for many clients over the years to include Tech Mahindra, Ralph Lauren, Silverstone Circuits, Cognita Schools, The Institute of Chartered Accountants in England and Wales and DZ Bank.

Landline Number: 02030 538 656
Mobile Number: 07780 847 535
Email Address:


Sandra Martins


Sandra Martins, 15 years’ experience in private practice, is a solicitor for Altor Employment Solicitors.

Sandra is a highly regarded solicitor who has been described by her clients and in The Legal 500 as ‘a fantastic asset’.

Sandra has always practised as a specialist employment solicitor. Her expertise and experience cover the full range of contentious and non-contentious employment law. She works closely with HR departments and senior management and provides practical legal guidance on all HR-related issues. In particular, she has extensive experience of advising on TUPE (including in an insolvency context), providing specialist support on corporate transactions and guiding clients through restructures and collective redundancies, including information and consultation obligations. She also regularly advises on executive exits and settlement negotiations.

She has particular and extensive experience of advising clients in the construction, recruitment, financial services, food manufacture and security sectors. Her clients have included two subsidiaries of the Morgan Sindall Group, Mitsui Sumitomo, Hatfield Philips, LNR Europe, Unilever and Premier Foods.

Sandra regularly represents clients in high profile tribunal claims. She recently led a team that defended over 500 individual and 10 union claims (on behalf of 500+ members), which arose after a client’s acquisition of an insolvent business. This included TUPE, redundancy, unfair dismissal and discrimination claims with a potential liability of over £17 million. Sandra successfully argued that there was no overall transfer of the insolvent business to her client, substantially reducing the potential liability and leading to the withdrawal or strike out of the majority of claims.

Sandra presents seminars and in-house training and regularly writes on employment issues. She is a member of the Employment Lawyers Association.

Sandra is fluent in Portuguese and speaks Spanish.

Landline Number: 0203 551 5771
Email Address:

Catrin Mills


Catrin Mills, 18 years’ experience in private practice, is a solicitor for Altor Employment Solicitors.

Recognised several times by Chambers and Partners and most recently in the 2017 Legal 500: “Catrin Mills has significant experience representing media and education sector clients in contentious matters, and represents high-profile companies, along with senior and board level employees, in the Employment Tribunal. Mills provides ‘clear, sound advice’ and ‘explains all available options’.

Catrin started her career with a City law firm and prior to joining Altor was a partner with Longmores Solicitors in Hertford.

Catrin advises organisations on all types of employment and HR issues, ranging from employee dismissals and grievances to complex reorganisations, collective redundancy, outsourcing, and TUPE, and has a successful track record of representing clients in employment disputes in the Employment Tribunal, County Court and High Court. Catrin also represents senior executives in severance negotiations.

Catrin has specialist sector experience of advising recruitment companies, and has advised extensively on issues relating to agency workers. Catrin also regularly represents clients in breach of confidentiality and restrictive covenant cases.


Shelley Hilsdon


Shelley Hilsdon, 7 years’ experience in private practice, is a solicitor for Altor Employment Solicitors.

Shelley is a specialist employment solicitor who delivers focused, commercial legal advice. She was noted as being ‘recommended’ by clients in The Legal 500.

Shelley trained and qualified as an employment solicitor at international law firm Dentons. She is experienced in advising clients on a range of contentious and non-contentious employment law matters including disputes and tribunal claims, employment documentation and corporate support.

Shelley acts for both employers and employees. She provides legal advice throughout the employment lifecycle: from drafting contractual documents, to providing support with employee relations, to negotiating exits and settlement agreements. She also has extensive experience of employment tribunal claims.

She is experienced in conducting employment due-diligence for corporate transactions, providing accurate and commercially focused reports to the client and advising on connected issues such as TUPE, redundancy and directors’ service agreements.

She has particular experience of advising clients in the transport, telecommunications, retail, media and financial services sectors. Her clients have included Virgin Atlantic, Heathrow Airport, NTT Docomo, Ralph Lauren and the Hilton hotel chain.

Shelley regularly writes on employment law topics and has delivered bespoke training to clients on issues such as disability discrimination and managing employee exits.

Landline Number: 0203 551 5772
Email Address:

Gill Craik

HR Consultant

Gill Craik, 20 years’ experience, is an HR Consultant for the clients of Altor Employment Solicitors.

Gill has worked for a wide range of entities across the private and public sectors, including commercial businesses, charities and not for profit organisations. Her realistic advice is based upon previous experiences gained in operational and commercial roles.

Gill is a fully qualified Fellow member of the Chartered Institute of Personnel and Development (FCIPD), and is currently studying for her Legal Masters in Employment Law (LLM).

Gill’s key skills and achievements include:

People management – Managed people ranging from small teams of 20 people to larger groups (200+ people) including multi-site and cross border teams.

Employee relations – Managed investigations and hearings for grievances and disciplinary matters (including appeals) and performance management issues. Successfully managed two warehouse closure programmes for an international engineering company.

Possesses a deep and broad commercial and operational mind-set. Empowers key leadership decisions through the provision of top level HR, business and operational advice, underpinned by thorough research and knowledge building.

Recruitment and selection – Successfully recruited a range of staff, including specialist roles.

Learning and development – Developed and delivered absence management and development programmes for clients in the engineering, charity, automotive and mobile assets sectors.

Influencing – Gained board approval for the development and training of a national absence management system and roll out across the UK, resulting in financial savings to the organization; guided a full complement of board members through the HR aspects of a complex TUPE process, redundancy consultation and change management programme to enhance services for its clients.

Gill has excellent communication skills; she is able to communicate and relate to staff at all levels, including staff forums, works councils, boards and trustees. She has coached executive teams to top levels of performance and draws on her extensive experience of enhancing skills and knowledge to win the confidence of business leaders and line managers on a range of company issues.

Mobile Number: 07976 093549
Email Address: