Two Labour MPs have submitted a motion of no confidence in party leader Jeremy Corbyn.
Margaret Hodge tabled the motion, her office has confirmed. It was seconded by Ann Coffey.
Earlier, Labour Leave campaigner Gisela Stuart used a victory address to call on party leaders to "reflect on how they represent the views of voters."
Without naming Mr Corbyn, she said: "It is now incumbent to all party leaders to also reflect to what extent they are representing and reflecting the views of the voters."
The leader of the UK's biggest trade union has said the country is 'riven' as a result of the EU referendum.
Len McCluskey told ITV News that the trade unions can help broker a peace deal and reunite the party now the "coup has failed".
Labour leader Jeremy Corbyn said he would 'reach out' to MPs that oppose his leadership but said they should 'respect democracy'.