Stephen Green, the former chairman of HSBC, has withdrawn from giving one of the opening speeches at the government-backed Global Law summit.

The ex-minister had been due to address the international conference alongside the justice secretary, Chris Grayling.

The three-day event next week has largely been financed by City law firms as part of the celebrations of the 800th anniversary of the Magna Carta.

The gathering, at the Queen Elizabeth II conference centre in Westminster, has been criticised by lawyers opposed to cuts in legal aid as distorting the legacy of the the medieval charter.

At the weekend Lord Green stood down from CityUK, one of the main financial organisations behind the summit. His presence at the Global Law summit following revelations about HSBC’s role in tax avoidance would have attracted further criticism.

In a brief statement, a spokesperson for the Global Law Summit said: “As CityUK has announced, Lord Green has stepped down as their chairman. He will therefore not be performing any public duties previously linked to that role, including the Global Law summit.”