An SNP backbencher has said a "fresh look" should be taken at her party's agreement with the Greens in the wake of the party dramatic defeat at the Rutherglen and Hamilton West by-election.

Michelle Thomson said the SNP needs to improve its messaging and questioned whether the two-year-old deal with the smaller pro-independence party was popular.

Humza Yousaf has promised the SNP will "reflect, regroup and reorganise" following the result of the by-election last Thursday, which saw Labour's Michael Shanks win on a swing of 20.4%.

Ms Thomson, MSP for Falkirk East, was campaign manager for Mr Yousaf's rival Kate Forbes in the leadership contest earlier this year.

READ MORE: James Mitchell: Rutherglen defeat will 'embolden' rebels

During the SNP race this spring both Ms Forbes and fellow candidate Ash Regan raised concerns about the deal and whether some policies pursued as part of the arrangement were damaging to the larger party.

Speaking to the BBC's Sunday Show, Ms Thomson, pictured below, said Mr Yousaf should "absolutely" remain the leader.

The Herald:

However, she added: "I do make the proviso, and I've said that before, that we need to look at our policies, we need to look at the proposition and we need to look at the messaging.

"We need to be speaking for the people of Scotland.

"We've got more work to do to acknowledge the result in the by-election."

READ MORE: John Curtice: Bute House Agreement not source of SNP's woes

The Bute House Agreement signed after the last Scottish Parliament election brought the Greens into government for the first time, gaining two ministers - Patrick Harvie and Lorna Slater - in a co-operation deal with the SNP.

Asked if the SNP should drop this, Ms Thomson said: "I would hope as part of the review that a fresh look is made at the arrangement with the Greens, I'm not sure how popular it is.

"But remember I'm only here as a backbencher, it is not my say so, it is Humza Yousaf's."

Ahead of the SNP conference later this month, Ms Thomson said there should be a renewed focus on the cost-of-living crisis.

Her comments reawaken concerns among some in the SNP over the benefits of the Bute House Agreement for the Scottish Government.

Long serving SNP MSP became one of his party's most prominent critics of the deal and in June voted against Ms Slater in a motion of no confidence over her handling of the now stalled deposit return scheme.

Mr Ewing was this month suspended for a week from the party at Holyrood over his actions in June. He has said he will appeal the decision.

In August he called for SNP members to be given another vote on whether the party should continue working with the Scottish Greens pointing to the decision by a former Greens leader Robin Harper to quit the party.

Mr Harper, who co-led the party before Mr Harvie, said the Scottish Greens had “lost the plot” and criticised his former colleagues over their stance on transgender rights and independence.

Mr Yousaf has repeatedly defended the Bute House Agreement  and made the continuation of it a central plank of his leadership campaign.

He told members during the contest the deal allowed the SNP, which does not have a majority in Holyrood, to govern with stability and rely on the votes of Green MSPs to get important legislation such as the budget passed.

Ms Thomson's comments today were seized upon by the Scottish Conservatives, who said the power-sharing agreement should be scrapped.

Party chairman Craig Hoy said: "Michelle Thomson is just the latest senior SNP figure to call for Humza Yousaf to think again about his toxic and destructive partnership with the extremist Greens.

"She, like the country, can see the deeply damaging influence Patrick Harvie and Lorna Slater are having on Scotland.

"On a host of policies - including vital road upgrades, the future of oil and gas, crippling fishing restrictions, gender self-ID and the bungled deposit return scheme - the Greens are either pulling the SNP in the wrong direction or out of their depth."