Nicola Sturgeon has refused to suspend a senior SNP politician after it emerged she is under investigation by a legal watchdog for alleged professional misconduct.

Tasmina Ahmed-Sheikh, one of the 56 SNP MPs elected in the 2015 general election, is the subject of an inquiry by The Law Society of Scotland over her former career as a lawyer.

She asked voters this week to re-elect her on June 8 as the Nationalist candidate for Ochil and South Perthshire, and said she was “co-operating fully” with the inquiry.

However, opposition parties have called on the First Minister to suspend the prominent candidate.

James Kelly, Scottish Labour’s campaign manager, has written to Ms Sturgeon, saying: “Any investigation by The Law Society is so serious that, if confirmed, the SNP must immediately suspend Tasmina Ahmed-Sheikh.

“The voters in Ochil and South Perthshire need immediate answers. They cannot go to the polls without all the information being made available to them.”

Murdo Fraser, the Scottish Conservative MSP, said that just four weeks from the election, the voters needed an “immediate explanation”.