The SNP’s deal with the Greens provides “certainty” to the party amid a challenging political landscape, Westminster leader Stephen Flynn has said.

During a campaign visit to Rutherglen and Hamilton West, he said Labour is acting like it is “entitled to win” at the upcoming by-election.

The Aberdeen South MP was knocking on doors alongside the SNP’s candidate, Katy Loudon.

Earlier, former SNP leadership contender Kate Forbes suggested her party should “check in” with members on the Bute House Agreement, which brought the Scottish Green Party into government after the last Holyrood election.

Speaking to journalists in Cambuslang, Mr Flynn said: “We’re all democracts, we can disagree without being disagreeable.

“It’s quite clear to me, certainly from speaking to colleagues in Holyrood, that in terms of the Bute House Agreement it offers certainty in what is a very challenging political landscape.

“Whether we like it or not, Holyrood is very polarised. And we need to make sure we can offer certainty to the people of Scotland in terms of budgets – in terms of the policy agenda that’s being taken forward.”

He added: “Peoples’ lives are very uncertain. The last thing they would want is for politicians to be navel-gazing at a time they should be focussed on the cost of living crisis.”

I think for a lot of people with traditional Labour values and traditional Labour principles, they’re very much shocked the Labour party have decided to go hand in glove with the Conservatives on this

The by-election in Rutherglen and Hamilton West was triggered by a successful recall petition for MP Margaret Ferrier, who was suspended from the House of Commons for breaching Covid rules.

While a date has not yet been set for the by-election, the seat will be keenly contested by Labour and the SNP.

Mr Flynn told the PA news agency: “I think the SNP’s going to do incredibly well in this by-election.

“The Labour party seem to be going around like this is already in the bag and I think they may well be in for a shock in that regard.”

He added: “We’re very focused on winning in this constituency and I think we can do just that.

“The Labour party are acting like they’re entitled to win this seat.”

He said about 1,300 people in the constituency had been impacted by the “heinous” two-child benefit cap, hitting out at Labour’s stance on the issue.

Mr Flynn said: “I think for a lot of people with traditional Labour values and traditional Labour principles, they’re very much shocked the Labour party have decided to go hand in glove with the Conservatives on this.”

On Angus MacNeil, who was recently removed from the SNP Westminster group, Mr Flynn said he would not give a “running commentary” on the ongoing disciplinary process.

Mr Flynn said he and his colleagues wanted a “positive outcome” but this was not always possible in politics.

First Minister Humza Yousaf told reporters on Wednesday that his party “overwhelmingly” backs the SNP-Green Party deal.

He said: “The membership has already of course had a vote, and voted overwhelmingly, 95%, to back the Green deal.

“I’d say to any politician trying to signal or suggest that we should move away from our climate proposals, to tackle the climate emergency would be unwise, particularly in August, the month after July, which is set to be, by the UN’s estimate, the hottest month in human history.

“So I think that it’s really important that the Green deal remains and of course I stood on a platform just over 130 days ago of retaining that Green deal, that co-operation deal that we have, and I’m pleased the SNP members backed me for leadership.”

Asked what a potential defeat in the Rutherglen and Hamilton West byelection could mean for his leadership, the First Minister said: “I don’t contemplate defeat.

“We are working to try to retain that seat and of course win the Rutherglen and Hamilton West by-election.

“We know it’s difficult circumstances – I’m not going to pretend to your viewers or listeners otherwise.

“And we know that Labour have already declared victory, but their complacency is for them to address. We will certainly not take a single vote for granted.”