The cash sum offered to prisoners from overseas who return home has almost doubled, the government has said.
The scheme was launched by ex-Home Secretary John Reid in 2006
Foreign national inmates will be given £1,500 if they leave the UK, up from the previous figure of £800, the Home Office has announced.
The payments will be on offer for five-and-a-half weeks as ministers try to fulfil a pledge to remove 4,000 overseas prisoners by the end of 2007.
A Home Office spokesman said: "We expect to hit the target."
But the Conservatives said the government was "desperate" and that it had resorted to offering "bribes".
The fund was launched in 2006 by John Reid, the then Home Secretary, in a bid to reduce overcrowding.
Inmates who came from beyond the European Economic Area were given £800 to help with fund their accommodation, education and resettlement in their country of origin.
As a result of the latest measure, any prisoners who apply to leave before 1 December 2007 and do so before 1 January 2008 can apply for up to £1,500.
The Home Office spokesman said the programme was "practical and cost-effective", and added that the government was on course to deport a record 4,000 inmates by the end of the calendar year.
But Conservative justice spokesman Nick Herbert said that this was only a fraction of the foreign national prison population.
He added: "Gordon Brown talked tough when he promised to remove all foreign criminals.
"Now it appears he is having to resort to larger bribes to beg them to leave."
In total, 2,784 prisoners from abroad were deported or removed between April 2006 and March 2007.