The Somerdale plant in Keynsham is set to close by 2011
MPs are to question senior officials from US food giant Kraft next month over its takeover of Cadbury.
Kraft announced plans earlier this week to close Cadbury's Somerdale factory in Keynsham, having previously said that it hoped to keep the plant open.
The move drew criticism from workers and Business Secretary Lord Mandelson.
Business select committee chairman Peter Luff said MPs wanted to know why Kraft went back on its pledge, and wanted it to clarify its position.
The committee cannot automatically summon foreign companies to give evidence, but Mr Luff said Kraft had already been contacted about the hearing.
The committee will also hear from unions representing Cadbury workers.
'Time for assurances'
Kraft completed its takeover of the UK chocolate maker on 2 February.
Plans to close the Keynsham plant, with the loss of 400 jobs, were originally announced by Cadbury in 2007 as it looked to move production to Poland.
Before its bid was accepted, Kraft told the BBC: "We believe we would be in a position to keep the Somerdale plant operating and we are sincere about that."
However it now says that it only become aware of how advanced plans for the new Poland factory were after the takeover deal had been agreed.
Mr Luff said the committee would look at "everything to do with the takeover bid, including its dealings with the government".
"The government opposed the bid, then embraced it and then Lord Mandelson criticised Kraft for closing the factory," he said.
"I think it's time for Kraft to give the assurances they've been giving in private to politicians in Parliament.
"It's been a very controversial bid. I think we would be failing in our duties if we didn't get Kraft to clarify their position."