Representatives of all three main political parties have told third sector leaders they would think again about the use of very large public service contracts, such as those offered by the Department for Work and Pensions.
At an election debate on Wednesday, Angela Smith, Minister for the Third Sector, said Labour was re-examining whether the DWP model, in which a small number of main contractors are appointed to carry out projects such as the Flexible New Deal, was the best value for money.
"I think the mindset is starting to change," she said. "Lots of senior officials in the DWP are listening to other opinions."
Although some third sector organisations have succeeded in winning large contracts, many smaller charities and social enterprises have found they do not have the resources to compete effectively.
Nick Hurd, shadow minister for the third sector, said he felt that contracts were not working and promised that his party would not offer large-scale contracts on the DWP model if it attained power.
Jenny Willott, Liberal Democrat third sector spokeswoman, said her party was also not in favour of large contracts.
The MPs were speaking at a debate held by specialist third sector lawyers Bircham Dyson Bell, held in its London offices, to mark the launch of a manifesto put out by a coalition of third sector groups, including chief executives body Acevo and the Social Enterprise Coalition.