Politicians who have the title ‘Sir’ normally get it after they retire. @Keir_Starmer is one the few to have the title while still active. Here’s a few other prominent ones of recent years (thread):

Starting with Sir Keir - @Keir_Starmer was made Knight Commander of the Order of the Bath (for senior military leaders and public servants) in 2014, after serving as DPP

Sir Menzies Campbell - @MenziesCampbell was made Knight Bachelor in 2004. Beat Chris Huhne and Simon Hughes in 2006 Lib Dem leadership election

Sir George Young - inherited the Young baronetcy of Formosa Place in 1960. Variety of ministerial roles since 1990

Sir Malcolm Rifkind - @MalcolmRifkind was made Knight Commander of the Order of St Michael and St George (the order for service in foreign and commonwealth relations) in 1997. Made a tilt in 2005 Tory leadership but withdrew before the ballots

Sir Anthony Meyer - soldier, turned diplomat, turned Europhile Tory MP. Inherited the Meyer Baronetcy at 15. Stalking horse against Thatcher in 1989. Lost by 314 to 33

Sir Keith Joseph - inherited the Joseph baronetcy of Portsoken in 1944. Education secretary under Thatcher

Sir Geoffrey Howe - made Knight Bachelor in 1970 upon appointment as Solicitor General. Contested Tory leadership in 1975 - came joint third behind Thatcher and Whitelaw in second round

Sir Alec Douglas-Home - made Knight of the Thistle in 1962. Renounced his peerage in 1963 to become PM and Tory leader

Sir Frank Soskice - Home Secretary under Wilson. Made Knight Bachelor in 1945 on appointment as Solicitor General

Sir Stafford Cripps - Chancellor under Attlee. Made Knight Bachelor in 1930 on appointment as Solicitor General

So, the (now abandoned) practice of giving the junior law officer a knighthood has a lot to answer for...

...and with no female equivalent of a baronet, there have been fewer opportunities for women politicians to wield a title. I wonder if @damekellyholmes or @J_Ennis have any political ambitions?