Two Labour MPs engaged in a very public spat over the future of the party on Tuesday, as Jeremy Corbyn's front bench reshuffle saw shadow culture secretary Michael Dugher fired.
Former shadow chancellor Chris Leslie, who is no fan of Corbyn, told the BBC's Daily Politics programme the reshuffle risked the "hard left" seizing control of the party.
But in tense exchanges, Cat Smith said the current shadow cabinet was more right-wing than the Parliamentary Labour Party and Corbyn needed a top team he could trust.
This morning Dugher became the first casualty of the reshuffle, losing the culture job. In recent days he had warned against Corbyn taking "revenge" on his critics inside the shadow cabinet.
Leslie, who quit the frontbench following Corbyn's election as leader in September, said he was not entire sure what Dugher's "sin" had been.
"I think he was very effective in opposing the government and opposing the Conservatives. I don't think removing him makes Labour's chances of winning any greater," he said.
"There is a natural impetus among the hard-left who want to tighten their control, they want to sideline moderate voices. I don't think anybody should be surprised, that is the nature of the hard left."
Leslie added that "the hard-left famously can not tolerate any dissent" and that voters were seeing Labour being taken over by "the disdainful hard left" which was "focusing inwardly".
But Smith hit back, questioning who exactly Leslie meant by the "hard-left" and insisted Corbyn, as leader, was free to pick his own team just as previous leaders were.
She asked Leslie: "Who are the hard left? Am I the hard left? We don't understand that language. I am a Labour MP and proud to be Labour. I am assuming you feel the same?"
"I think Jeremy Corbyn, as leader of Labour Party is within his rights to pick the people who want to serve in the shadow cabinet," she said.
"If he doesn't want people in his shadow cabinet who spend more time attacking the Labour Party leadership than the Tory benches opposite us, then he is perfectly within his rights to do that."
Smith, who is shadow minister for women and equalities, said Corbyn was in a "very strong" position to move the shadow cabinet to the left.
"He is trying to realign his top team to match more what the PLP is and more what the party is. I think the current shadow cabinet is frankly to the right of where the PLP is," she said. "It's right Corbyn has a team around him he trusts."
Today's reshuffle followed speculation of a possible "purge" of those with views at odds with the leader, including shadow defence secretary Maria Eagle's support for the renewal of the UK's Trident nuclear deterrent.
Another nine shadow cabinet members voted for air strikes after Corbyn was forced to allow a free vote - fuelling suggestions that he could replace them with left-wing supporters.
But the scope of the changes appeared increasingly likely to end up narrower than mooted, as the leadership sought to balance the desire for a coherent message on the front bench with the major backlash in the parliamentary party that would greet any move to freeze out moderates.