The home secretary is set to make concessions on his anti-terror proposals, the Conservatives have predicted.

Charles Clarke will be presenting his plans to parliament on Monday, but is facing continued opposition to the introduction of "control orders" from both opposition parties.

In a bid to win over critics, he is widely expected to offer some concessions when he outlines the plans to MPs.

Shadow home secretary David Davis indicated that without some movement the House of Lords could block or amend the plans.

Under the current proposals, it will be Clarke himself who first issues the control orders, which could range from limiting access to mobile phones to imposing house arrest.

"I would be very surprised if tomorrow the home secretary doesn't concede that the decision has to be made by a judge," Davis told BBC1's Breakfast with Frost programme.

"There is a lot more to it than that. There is the question of the levels of proof, the way we handle this sort of thing.

"There is a whole series of other things that have to be sorted out.

"There are a lot of changes to come and I think that if they don't come in the Commons, the Lords will force them on him.

"I am going to encourage the Lords to challenge the argument, make sure we are getting the straight facts, make sure we do the best we can to defend British liberties."

However Home Office minister Caroline Flint indicated the government was sticking by its initial view that a minister, not a judge, should issue the control orders.

"In terms of national security, it is the government that is responsible for protecting the public," she told BBC Radio 4's the World this Weekend.

"I think it is absolutely right that in those circumstances it is the home secretary, based on the information that he is given."

She added that the government decision "will be subject to judicial involvement which can turn round and say 'no'. That is very clear within the Bill."

Meanwhile, Liberal Democrat leader Charles Kennedy has confirmed that there have been continued behind-the-scenes discussions in a bid to reach agreement.

"There has been movement... whether the movement will be enough remains to be seen," he said.

"Whether this all gets to the House of Lords could be entirely a different kettle of fish completely. I think this particular story has got a long way to run yet."

Kennedy also warned ministers that his party would not be "retreating from basic, bottom-line fundamental principles".