Gareth is a partner in Russell Cooke's trust and estate disputes team and specialises in all types of work undertaken in this specialist team, including bringing and defending challenges to wills; disputes with personal representatives; trust and estate administration disputes and bringing and defending claims under the Inheritance (Provision for Family and Dependants) Act 1975.

Gareth has considerable experience in contested applications brought in the Court of Protection relating to the property and financial affairs of people who lack the necessary mental capacity to do deal with that property themselves.

Much of his work involves an international element, and he has particular experience in dealing (in conjunction with the firm's specialist French law team) with matters arising in estates with assets in England and France. Gareth is also a fluent French speaker.

He is described in The Legal 500 (2017) as "clever as well as practical", "very knowledgeable" and "great with clients". In 2016, he was praised by The Legal 500 (2016) for his willingness to “work hard to keep costs down where possible” and as someone who is "always ready to go that extra mile". In 2014, The Legal 500 commented that he "is very experienced and attuned to the needs of his clients". He was also recommended in The Legal 500 (2012) which notes that he "holds his nerve when the going gets tough".