Alastair is Chair of the British Liver Trust - the national liver charity - focusing on liver disease and liver cancer. The British Liver Trust reaches over a million people each year, raising awareness of the risk factors of liver disease and liver cancer, as well as supporting those with these conditions. 

Alastair is a Trustee for the Royal Regiment of Scotland Trust, which provides vital welfare, benevolence, and financial support to serving soldiers, veterans, and their families, granting over £2.5 million to date.

Alastair is Chair of The Drinking Fountain Association which gives grants for the creation of new drinking fountains and the restoration of existing fountains.

Alastair sits on the Governing Bodies of Samuel Wilsons Loan Trust, which offers business loans to young people (aged 18-39) for establishing and developing new businesses, and who are "in need by reason of ill-health, disability, financial hardship or other disadvantage." 

Alastair acts as Deputy Chairman for The Emanuel Hospital Management Sub (Court of Aldermen) Committee.  The Emanuel Hospital charity was founded in 1600 after a bequest by Lady Anne Dacre to set up an almshouse to provide homes for 20 older people and education for 20 children. The charity is now administered by the City of London Corporation.

Alastair nominated Homewards - a programme of The Royal Foundation of The Prince and Princess of Wales - as the charity he would support during the course of his Mayoral year, as part of the Lord Mayor's Appeal. The charity's mission is to demonstrate that it is possible to end homelessness by making it rare, brief, and unrepeated.

Alastair has been a Trustee since 2018. The Morden College (Charity founded c. 1703)is dedicated to supporting and providing residential care for senior citizens.