Sir Keir Starmer was pressed on the two-child benefit cap by SNP Westminster leader Stephen Flynn during his first PMQs as Prime Minister on Wednesday.
He hit back: “I would just say this before he lectures everyone else, he should explain why since the SNP came to power there are 30,000 more children in poverty in Scotland.”
SNP MP Pete Wishar then asked: “Is [Sir Keir’s] honeymoon over before it even begun?”
Having spent four years as opposition leader, the Prime Minister swapped roles with Mr Sunak for the parliament showdown and answered MPs’ questions from the Government front bench.
Sir Keir’s decision to remove the whip from seven Labour MPs over their votes against a two-child benefit cap is an early show of ruthlessness from the new administration.
Former shadow chancellor John McDonnell, ex-business secretary Rebecca Long-Bailey, Apsana Begum, Richard Burgon, Ian Byrne, Imran Hussain and Zarah Sultana have been suspended from the parliamentary party.
The House of Commons voted 363 to 103, majority 260, to reject the amendment tabled in the name of SNP Westminster leader Stephen Flynn.
The cap, introduced in 2015 by then-Conservative chancellor George Osborne, restricts child welfare payments to the first two children born to most families.