A leading member of the Unison union has warned the government that it faces trench warfare over plans to establish foundation hospitals.

Pledging to mobilise grassroots support to frustrate the government's flagship NHS policy, Karen Jennings has said the government is in for a "serious rocky ride" during the party conference season.

Following the recent Commons rebellion, Jennings predicts there will be "a fight in the House of Lords" when the legislation goes before peers in the autumn.

She warns that Labour MPs and peers are in no mood to compromise with ministers.

"It's perfectly clear that there's been no consultation. The parliamentary Labour Party are furious - they haven't been consulted," she told this website.

"There's been no green paper, there's been no white paper, the legislation on foundation trusts has been rushed through, there's been a little bit of tinkering at the edges around amendments, but this has been railroaded through without any consultation."

Jennings, the union's national health secretary, warns that the government faces stiff opposition even if the legislation is passed.

"What we're absolutely clear about is if the Labour government does have its way on this, in relation to the bill, we still will not stop there," she said.

"We have a very, very strong branch network and we will be working very closely with those branches to ensure that the second wave... is halted."

The recent clash over foundation hospitals is indicative of a deeper sense of disconnection between the government and its supporters.

"I think that there are people now beginning to wake up to the fact that you cannot deliver a good policy through a small number of specialist advisers," she said.

"I think that foundation hospitals is the tip of the iceberg in terms of the discontent that is now mounting."