Wes Streeting accused Labour’s seven suspended MPs of being “naive” over their decision to vote against the government.
A handful of leftwing Labour MPs supported an opposition amendment to drop the two-child benefit cap – a policy which stops parents from claiming state help for their third child – on Tuesday.
PM Keir Starmer then unexpectedly chose to kick the rebels out of the party for six months.
Sky News presenter Wilfred Frost asked the health secretary this morning: “Did it reveal a word that’s been using occasionally about him, but in full, the ‘ruthlessness’ of the prime minister?
“And if so, is that actually a good thing, is it something you welcome?”
“I think it shows discipline,” Streeting replied.
Streeting said that part of democracy is having disagreements, and he is “comfortable being challenged by members of parliament, including people within my party, about decisions I make”.
However, he suggested this particular occasion was an exception, because it was a vote related to the King’s Speech where a government sets out its plan for the next year.
Streeting said: “A King’s Speech is the government’s programme and the first King’s Speech in particular is important.
“Labour MPs were elected to deliver the King’s Speech.
“The days of politics as performance art are over. We are in government to deliver. Everyone knew that.
“For seven people to choose to showboat or choose to use politics as performance art and to expect there not to be circumstances was naive at best.”
He said Labour are “in government to deliver”, and will do so on child poverty.
Frost previously criticised Labour for not sending a minister to speak to Sky News the morning after the rebellion, describing the act as “disgraceful”.
He told Sky’s Kay Burley on Wednesday: “As we know better than most in this business on the breakfast show, it leaves you hanging without much to do instead so it’s rather disrespectful on top of that.
“Again, three weeks into the new government, they’re sending a message loud and clear by suspending the whip.
“You’ve got to back that message up the following day.”