The Conservative leader told Tony Blair that "little or no progress has been made on the central objectives which you set for the British presidency".
Recalling that Mr Blair launched the Presidency at Waterloo Station in London six months ago, Mr Hague said one of the top priorities was to get negotiations for EU enlargement "off to a flying start".
Mr Hague said: "After six months, it looks farther away than ever."
He quoted Finnish leaders as saying enlargement was more problematic now than it was a year ago, and added that the Prime Minister had promised to tackle the "cost and weight" of the Common Agricultural Policy: "But we are no nearer to fundamental reform of the CAP," Mr Hague claimed.
Mr Hague said: "One European leader told me in Cardiff that during this presidency he has had his photograph taken more often than ever before, but was never asked to reach a substantive decision.
"For all your fine words, at the end of the British presidency we are left with the cost and weight of the CAP continuing to grow year by year."
But the Prime Minister yesterday hailed the Cardiff Euro-summit as marking "a solid step forward towards a more effective and better accepted European Union".
In a detailed Commons statement, he claimed Britain's six-month presidency had re-established strong, positive relations with its EU partners.
In a sideswipe at the previous Tory Government, Mr Blair said: "After years of negative and destructive posturing that isolated Britain in Europe but did not advance our interests, we have re-established strong, positive relations with our EU partners. I believe those relations, not before time, are transformed and for the better.
"That is good for Britain, for Europe and for Britain in Europe. Cardiff was the proof of that."
Sidestepping the question of Britain's entry to the European single currency, Mr Blair's statement covered the four main themes of the summit: economic reform and employment; enlargement and the necessary accompanying policy reforms; the future development of the EU; and foreign policy issues, notably Kosovo.
"We also discussed a range of other questions which touch the lives of ordinary people: the environment, crime and drugs, the millennium bug."
Other subjects discussed included the Middle East peace process, India and Pakistan, Indonesia, East Timor, and Northern Ireland, as well as the problem of drugs.Reuse content