Anas Sarwar has been warned his election pledge of “no austerity under Labour” has come back to bite him amid reports the UK Chancellor will announce a £20 billion black hole.

On Monday, Chancellor Rachel Reeves is expected to unveil a public finances shortfall which the SNP has warned could lead to cuts or tax increases.

The Scottish Labour leader is now facing criticism after he used a General Election leaders’ debate to state: “Read my lips – no austerity under Labour”.

The comment came after SNP leader John Swinney said during the same debate Labour’s plans would lead to £18 billion of cuts.

National Wealth Fund Taskforce
Chancellor Rachel Reeves is expected to make a speech on public finances on Monday. (Justin Tallis/PA)

Ahead of the Chancellor’s speech on Monday, SNP MP Dave Doogan said cuts and tax rises were “repeatedly dismissed” by the Scottish Labour leader.

In a letter to Mr Sarwar, he said: “That comment has rapidly come back to bite you. The new Labour Chancellor has blown your election promises apart – so what are your lips saying now?”

He added: “People will rightly be concerned that Labour lips were prepared to promise the public one thing to win votes during the General Election but are now saying the exact opposite within weeks of taking power.

“Alarm bells are now ringing that the Labour Government plan to continue Tory cuts and public services will be starved of the cash they need – just as we have seen with the failure to scrap the two-child benefit cap this week.

“I hope we can agree that Scotland’s public services cannot afford another five years of Westminster cuts.”

Mr Doogan also urged Mr Sarwar to “direct you own MPs to serve Scotland’s interests and join with the SNP to vigorously oppose fresh Westminster austerity, even if that austerity is now being prepared by your own Labour Chancellor”.

Earlier, SNP Westminster leader Stephen Flynn said the Chancellor should “apologise for misleading voters” during the election campaign.

Scottish Labour’s deputy leader Dame Jackie Baillie said: “Unlike other parties, Labour has always been honest with the public about the mess the Tories created, but we will keep our promises – there will be no return to austerity.

“The Tories crashed the economy but Labour is acting as quickly as possible to stabilise it and deliver the growth Scotland needs.

“Labour has a plan to create jobs, raise wages, invest in our NHS and turn Scotland into a clean energy superpower and our Scottish Labour MPs are already hard at work delivering it.”