SJ Berwin has lost longstanding corporate partner Jonathan Djanogly, who has left the top 20 firm to focus on his political career.

Djanogly, who is the Conservative MP for Huntingdon and the shadow solicitor general, retired from the partnership in July and officially left the UK limited liability partnership (LLP) in August – making him one of six partners to leave the LLP in the last two months.

If the Conservative Party wins the next general election, Djanogly, who spent 21 years with SJ Berwin and was admitted to the partnership in 1998, is hoping to take up the solicitor general role. The position, currently held by Vera Baird QC, entails serving as deputy to the attorney general, overseeing the work of the Crown Prosecution Service and the Serious Fraud Office in England and Wales, as well as advising the Government.

Commenting on his move, Djanogly said: "I retired back in July because we [the Conservative Party] are hopefully going to win the election and I will hopefully be a minister. This was the appropriate time to stand down and I am confident enough in the outcome of the election."

In total, six City partners have retired from the firm's UK LLP since the beginning of August. London telecoms partner Michael Bywell has moved back to his native New Zealand while corporate partner Polly Daines has left to re-train as a primary school teacher. Corporate partner Joanna Hamilton has retired, and tax partner Adrian Brettell has taken on a consultant role.

Former structured finance head Brian Carne, who left the firm earlier this year to start his own structured finance advice company, also officially exited the partnership.