Tory leader David Cameron has made a “comprehensive offer” to the Liberal Democrats to work with him in parliament.

A hung parliament was declared this morning and although the Conservatives won the most votes, they do not have an overall majority.

Giving a speech at 2.45pm this afternoon, Mr Cameron said that his party would compromise with the Liberal Democrats on some issues but would not offer a referendum on radical electoral reform that Nick Clegg has called “non-negotiable”.

He said it was “already clear that the Labour government has lost its mandate to govern our country”.

Addressing the Liberal Democrats, he said: “I want us to work together in tackling our country’s big and urgent problems.”

Whether the offer will be a coalition or a more informal agreement remains to be seen, as does the question of whether the offer could see Liberal Democrats in the cabinet.

He declared there could be no compromise with the party on defence and Europe, although he offered an all-party committee of inquiry on political and electoral reform to look at the possibility of changing the first-past-the-post voting system.

He also cited education policy and creating a low-carbon economy as areas in which the parties could agree.

Mr Cameron would not go as far as offering a referendum on the issue and refused to take questions when he finished speaking, saying that this was an “urgent issue”.

Mr Clegg has acknowledged that his party’s result has been “disappointing”.

With just three more seats to be counted today, his party has lost five seats and currently has 57.

He said today: “It seems this morning that it is the Conservative Party which has more votes and more seats – although not an absolute majority – which is why I now think that it is the Conservative Party which should seek to govern in the national interest.”

Gordon Brown also offered Liberal Democrat leader Nick Clegg a power-sharing deal this afternoon, although he said he would be” willing to see any of the party leaders”.

Speaking outside Number 10, he said: “On the critical question on the formation of a government that can command a parliamentary majority I have of course seen the statements of other party leaders. I understand and completely respect the position of Mr Clegg in stating that he wishes to make contact with the leader of the Conservative party.

“As you know we already have in place mechanisms and facilities that will give the political parties any civil service support they need. Mr Cameron and Mr Clegg should clearly be entitled to take as much time as they see necessary.

“For my part I should make clear that I would be willing to see any of the party leaders. Clearly if the discussions between Mr Cameron and Mr Clegg come to nothing then I would of course be prepared to discuss with Mr Clegg the areas where there may be some measure of agreement between our two parties.”

Mr Brown said two areas in particular where talks could focus would be ensuring economic stability and reforming the voting system.