Liberal Democrat leader Nick Clegg asked the PM why the taxpayer-owned Royal Bank of Scotland was prepared to lend money to Kraft to fund the 11.9 billion bid.
"When British taxpayers bailed out the banks, they would never have believed that their money would be used to put British people out of work," Mr Clegg said.
But Mr Brown pledged yesterday that the government would do "everything we can" to make sure jobs are kept in Britain.
The Prime Minister said assurances had been sought from Kraft about the US company's commitment to the Cadbury name, workforce and quality after its approach was recommended for approval.
Kraft yesterday announced the backing of the Cadbury board for a revised 840p per share offer in a move set to end the independent history of the British firm.
Kraft investor Warren Buffett brands Cadbury purchase 'a bad deal'