RADICAL new plans to boost the number of Scottish Liberal Democrat parliamentarians will be unveiled by party leader Willie Rennie after he said a lack of diversity was "plaguing" his party.

The Mid Scotland and Fife MSP has put forward a motion to his party's conference, to be held in Edinburgh next month, after admitting that the party's record for electing people from diverse backgrounds did not reflect its values.

The LibDems have been stung by criticism after Alison McInnes, its only female MSP, lost her place at the top of the party list for May's elections despite winning plaudits for her performance at Holyrood. At Westminster, every one of the party's eight MPs is male.

The situation has convinced Mr Rennie that he should take action, despite members of his party traditionally being against affirmative action or quota systems.

If approved, his plan would see the top candidate at the 2019 European elections be female and candidates for the top five Liberal Democrat target seats at the 2020 general election selected from all women shortlists.

At the Holyrood elections in 2021, candidates in at least five of the 10 most winnable seats, whether constituencies or top regional places, will be women. It will also see a gender balanced group of party spokespeople appointed and a new campaign diversity fund established.

Mr Rennie said: "Our record for electing people from diverse backgrounds does not reflect Scottish Liberal Democrat values of equality and opportunity. But these proposals give us the chance to make this year a turning point for our party.

"We’ve tried a range of schemes to try and improve diversity but it seems bolder action is now needed. The Scottish Liberal Democrats is hungry to build a fresh, energetic and radical political machine that advances liberal values and it’s time to right the imbalance that’s been plaguing us for far too long.

"As a party we have a positive, liberal and bright vision for the future of Scotland that includes people from all backgrounds. By changing, we can send a message to liberal-minded voters that we are serious."