Tory factions, coalition ministers and business leaders heaped pressure on David Cameron as he prepared to deliver his speech on Britain's place in the European Union.

The Prime Minister is facing a seemingly never-ending string of demands about the direction the UK must take ahead of Friday's address in the Netherlands.

Labour leader Ed Miliband warned that Mr Cameron was about to take Britain "to the edge of an economic cliff" by creating uncertainty for business, while Lib Dem Business Secretary Vince Cable warned him not to take a "dangerous gamble" with the national interest.

Mr Cameron will be particularly keen to balance the competing demands from within his own party and the business world as he sets out his vision for a fresh settlement with Brussels.

Eurosceptics in the City have called on him to offer Britain "a clear choice" over its membership of the European Union. In a move to counter pro-Europe business leaders' claims that firms want Britain to remain in the EU, figures including banker and Conservative peer Lord Flight, venture capitalist Jon Moulton and former Barclays director Lord Vinson called for an in/out referendum.

In a letter to the Daily Telegraph, the signatories said: "Pressure is growing from all sides for a referendum on our membership of the EU, not least because of the movement towards full banking and political union within the next five years."

Mr Cameron also faces a deluge of demands from formal and informal groupings of backbenchers from across his party, including a number of former Cabinet ministers.

The Prime Minister has rejected calls for an immediate in/out popular vote but is expected to announce plans for a referendum on a new settlement with Brussels after the 2015 general election.

Former defence secretary Liam Fox urged the Prime Minister to show "courage and conviction" and called for British voters to eventually be given a "clear in/out choice".

Writing on the ConservativeHome website, Dr Fox said: "Ending the concept of 'ever closer union' by negotiating a new agreement - on the basis that it will settle the European question in Britain for a generation with a clear in/out referendum choice for the British people based on renegotiation - is what many of us hope we will hear from the Prime Minister tomorrow."