Theresa May was told the government is “falling apart” after her ministers were forced to accept a raft of Labour Party amendments to the Budget.
The Tories avoided a Commons showdown by supporting four changes to the Finance Bill on Tuesday night in a move which underlined how fragile the Prime Minister’s premiership is amid Brexit chaos.
It comes a day after the DUP threw into doubt the “confidence and supply” arrangement the Northern Irish party struck with the PM after the 2017 snap election when her majority in parliament was stripped away.
On Tuesday, the government agreed to SNP calls for a review of the public health effect of gambling and a review of the effectiveness of the Government’s new tax avoidance measures.
Labour amendments approved included seeking a report detailing the impact of measures to require disclosure of information about certain cross-border tax arrangements under different Brexit scenarios.
A second asked for a review of the effects of the Government’s new tax avoidance measures on households with different levels of income, on child poverty, people with protected characteristics and on a regional basis.
The Government climbdown and unwillingness to force votes came after the DUP voted with Labour once and abstained five times during Finance Bill votes on Monday.
May brokered a deal with 10 DUP MPs after the last election with a controversial £1bn funding deal for Northern Ireland.
However, tensions over Brexit have cast doubt on the arrangement and led to the DUP withdrawing its support.
Shadow chancellor John McDonnell said in a statement outside the Commons: “It’s absolutely staggering that the Government has accepted all Labour amendments to the Finance Bill because it couldn’t rely upon the DUP’s support.
“The Tories are in office but not in power. We’re watching a government falling apart in front of us.”
During the second day of committee debate on the Bill, Treasury minister Robert Jenrick warned the cost of slashing the maximum stake on fixed-odds betting terminals (FOBTs) must not be paid for by cuts to doctors and teachers.
He said ministers were not using the issue to boost exchequer revenues, after the government made an embarrassing U-turn over the timing of the reduction in the top wager from £100 to £2 to combat problem gambling.
The change will come into force in April after more than 70 MPs set out to sabotage Treasury plans to push it back to October.
That delay sparked the resignation of sports minister Tracey Crouch as well as condemnation from MPs who believed the cut was vital to protect vulnerable people and families.
Jenrick later said the Government would accept the SNP’s amendment which called for a review of the public health effect of gambling, noting it was limited in scope but that Public Health England had already been commissioned to review “problem gaming”.
He told MPs: “In respect of new clause 12 ... I am content for the Government to support that, but I’d simply say it is very limited in scope, so I wouldn’t want to raise expectations that that will achieve all of the goals she seeks.
“But perhaps that allied to Public Health England’s work will help to continue the public debate on this matter.”
Later in the debate, Conservative Bob Stewart (Beckenham) said some international companies are “behaving appallingly” in the way they handle their tax affairs and the Government “must sort that out” as he raised concerns over the amount of tax paid by some multinationals in relation to their profits.
Financial Secretary to the Treasury Mel Stride maintained the Government had provided “international leadership” on the issue.
Shadow Treasury minister Anneliese Dodds called for a “far more serious and engaged approach to countering tax avoidance and evasion”.
Dodds, commenting in relation to Brexit, said: “So far the Government has been incredibly vague about what commitments it will make on tax matters in relation to preventing avoidance and evasion.
“Furthermore, we’ve had some very, very unhelpful - to put it extremely mildly - comments coming from Government about whether they might seek to undercut the rest of the EU on tax matters.”