Britain could drift out of the European Union unless the bloc meets key challenges, Prime Minister David Cameron was to have said in a speech on Friday that has been postponed by the Algeria hostage crisis.
According to extracts of the speech given to the media before the speech in the Netherlands was called off on Thursday, Cameron was to have said that Britons were tiring of the EU's "lack of democratic accountability".
"If we don't address these challenges, the danger is that Europe will fail and the British people will drift towards the exit," Cameron's speech in Amsterdam was to have said.
"I do not want that to happen. I want the European Union to be a success and I want a relationship between Britain and the EU that keeps us in it."
Many British media organisations had flown reporters out to Amsterdam to cover the speech, who stepped off the plane to hear almost immediately that Cameron had postponed it.
The extracts did not contain a widely expected announcement of plans to renegotiate Britain's EU membership and to put the new terms to the British public in a referendum.
But Cameron was to have defended his decision to ask "difficult questions" of the EU despite its fragile economy, following criticism from European partners, the United States and business leaders.
He was to have outlined three key challenges for the EU: the eurozone crisis, lack of competitiveness compared to emerging nations, and a "lack of democratic accountability" that is "felt particularly acutely in Britain".
In extracts from the speech, Cameron was to insist that many European citizens increasingly saw the EU as imposing painful austerity without their consent to "bail out governments on the other side of the continent".
"And yes, of course, we are seeing this frustration with the EU very dramatically in Britain. Europe's leaders have a duty to hear these concerns. And we have a duty to act on them."
Cameron postponed the speech late Thursday after indicating that several Britons could have been killed in the Algerian army offensive to free hostages from Islamist kidnappers at the BP-operated In Amenas gas plant.
His Downing Street office said a "new date and venue" would be announced in due course.
It is the latest in a series of delays for the speech, which comes as Cameron faces pressure from the eurosceptic right wing of his Conservative party to take a stand on Europe, an issue which has long divided the party.
Plans to give the speech first emerged six months ago, followed by reports that he would give it at Christmas, and then it was put back to mid-January. Cameron joked that the long delays were due to his "tantric" approach.
It had been widely expected on January 22 but Cameron pulled it forward to Friday when it emerged that it clashed with commemorations for the 50th anniversary of Franco-German reconciliation following World War II.
By coming to Europe, Cameron had intended to follow in the footsteps of previous British prime ministers who have made major European policy speeches on the continent.
In 1988 Margaret Thatcher spoke in Bruges, Belgium, while Tony Blair spoke in Warsaw in 2000. Winston Churchill meanwhile called for a "United States of Europe" in a speech in Zurich in 1946.