Rishi Sunak has refused to commit his party to supporting the triple lock on the state pension beyond the next general election.

The Prime Minister stopped short of giving a categorical Yes when asked if would make the promise by SNP Westminster leader Stephen Flynn.

Mr Sunak said he remained committed to the policy in principle, but did not provide a timeframe.

The triple lock currently guarantees the state pension will rise in line with the higher of three options - average earnings, inflation or 2.5%.

The Office of National Statistics (ONS) yesterday reported that average earnings in September were 8.5%, which would ordinarily set the bar for the rise in April. The rise last year was 10.1%.

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It led to calls for a rethink of the policy, which was started by the Tory-led Coalition in 2010, with former Tory leader Lord William Hague calling it a costly “runaway train”.

Work and Pensions Secretary Mel Stride also admitted that in the long term the triple lock was unsustainable, and there was speculation the policy could be suspended to help the Tory government find £600million for tax cuts ahead of the election.

At PMQs, Mr Flynn said that “as someone who spends more money heating their swimming pool than the total value of the UK state pension”, Mr Sunak was not especially invested in the issue. 

But he went on: “Let's afford him the opportunity to clear up any confusion. 

“Will he commit his party, the Conservative party, to maintaining the state pension triple lock beyond the next general election? Yes or no?”

Mr Sunak replied: “This is the party that introduced the triple lock. This is the party that has delivered a £3000 increase in the state pension since 2010. It's also the party that’s ensured that there are 200,000 fewer pensioners living in poverty today.

“And, this winter, ensuring that pensioners get an extra £300 alongside their winter fuel payment to support them through the challenging times with inflation. 

“So Mr Speaker, our track record is clear. There is one party in this house that is always stood up for our pensioners and that is the Conservative party.

The Herald: Stephen Flynn

Mr Flynn said: “I don’t think we heard a Yes there. 

“You’ll imagine my shock, my utter surprise, that we appear to have consensus once again between the Conservative Party and the Labour Party on this most important of issues.

“Despite the promises that were made to the people of Scotland in 2014 and despite the clear statements from the likes of Gordon Brown that the only way to protect your pension is to remain within the UK. How hollow those words are now.

“I ask the Prime Minister, who does he think will scrap the state pension first, his Government or the Labour Party's government?”

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Mr Sunak said it was thanks to the UK Government that pensioners in Scotland were getting “record increases” in their state pension of £870 this year and other help

“This is the government that introduced and remains committed to the triple lock.

“But he does raise a good point. Pensioners in Scotland should know the reason they can rely on the state pension not just today but for years to come is because of the strength of our union and the strength of our United Kingdom government.”

Later, Ashley Dalton, the Labour MP for West Lancashire, said she was “still confused” on the issue after Mr Sunak’s exchange with Mr Flynn.

She told the PM: “Just yesterday, the Secretary of State for Work and Pensions said that the pensions triple lock is not sustainable, the Chancellor's economic advisors have suggested that it is time to review the policy, but Number 10 when questioned have said they're committed to it. Which is it?”

Mr Sunak replied: “This government is committed to the triple lock, it was this government that introduced the triple lock.

“She might want to have a word with her own deputy leader, who I don’t think provided much clarity on the matter. I think we all know and remember [that] when it came to pensions, what 

we can remember is Gordon Brown’s 75p a week increase.”

Speaking after PMQs, SNP MP David Linden said: “It's increasingly clear that Scottish pensions are under threat from Tory and Labour Party cuts - with Rishi Sunak and Sir Keir Starmer both failing to back the triple lock.

"Unlike Sunak and Starmer, the SNP is committed to the triple lock, we oppose yet another increase in pension age, and will always fight to protect pensions from Westminster cuts."