After meeting Tony Blair in Downing Street, the Conservative leader Michael Howard said: "There's a great desire at a time when the country faces such great danger to work together.
"We are all in this together and we all believe it is very important to show that the country is united in its response to the danger we face. And we hope that it will be possible to reach agreement on further measures that will enable us to deal with this threat more effectively."
The Liberal Democrat leader Charles Kennedy welcomed the "reasonable progress" and vowed to continue to ensure that basic civil liberties were not compromised.
During their discussions, they discussed strategies for combating terrorism in the aftermath of the London bomb attacks.
Mr Howard said the Prime Minister had undertaken to consult with the opposition party leaders again, possibly at the end of August or the beginning of September, on firm proposals.
The Tory leader was asked whether a possible recall of Parliament during the summer recess was raised.
He said: "We discussed the possibility of a recall of Parliament. I think that will depend on events. We are not pressing for a recall of Parliament for the sake of it.
"If, heaven forbid, something happens which makes it important for Parliament to have the opportunity to question and debate, I'm sure that that will happen. Indeed, we have an assurance from the Prime Minister that would happen."
Mr Howard said he had pressed Mr Blair on the Tory call for electronic intercept evidence to be admissible in court.
The Tory leader said: "We have put forward a detailed scheme which we believe would meet all the concerns that have been expressed about that possibility, and that is being looked at seriously."
Mr Howard voiced reservations about a police call to be allowed to hold terrorist suspects for up to three months without charge.
He said: "So far as the three-month period of detention which the police have asked for, we see very considerable difficulties in that. That is a long time to hold someone without charge, and possibly just release them after that.
"That is being looked at by the Prime Minister, and in due course they will come forward with their proposals and tell us what they intend to do about that."
Mr Kennedy said that his party retained reservations over the extension of detention periods and there were issues to be resolved over the use of intercept evidence, he said.
"We are all anxious to get as much constructive and responsible agreement as we can achieve with the prime priority - that is the responsibility of all of us as representatives - which is the safety of the British public, both those who live in this country and those who are guests and visitors.
"But equally, and I say this very much as a Liberal Democrat input in all of this, to make sure that we go about this in a measured way - and I am certainly satisfied that that is the attitude of the Government - and that we don't surrender basic civil liberties in the process.
"It is very important that that is borne in mind and we will work with the Government and the Conservative Party very much on that premise."
Asked if he would countenance any lengthening of the right of police to hold suspects without trial, he pointed out that the 14-day limit was already an extension.
He said more information was needed before a political judgment could be made on that issue.
The Home Secretary Charles Clarke, emerging from the meeting, said: "We've had very positive discussions this morning. There's a great deal to talk about.
"I certainly have the feeling all parties are continuing to work together to put forward the right legislative programme that we have to deal with. We will maintain contact throughout the summer and we will have intensive discussions in September about the issues we've talked about.
"But very constructive overall."Reuse content