Former French President Valery Giscard d'Estaing has criticised the UK for achieving "very little" so far in its presidency of the European Union.
Mr Giscard d'Estaing said the UK was distracted by the 7 July bombing
The UK took over the rotating presidency on 1 July and will hold it until the end of the year.
Mr Giscard d'Estaing said the "horrible" 7 July bombs had distracted the UK from EU business.
But UK Europe Minister Douglas Alexander said the UK was working hard behind the scenes on key issues.
Mr Giscard d'Estaing, , who oversaw the drafting of the EU constitution in 2003-4, said he did not blame Britain.
He said the problem was the rotating EU presidency, which the constitution would have replaced with a permanent post for a high-level European politician.
The constitution was rejected by voters in France and the Netherlands earlier this year, and has now been shelved until the French presidential election in 2007, at the earliest.
"What we propose, to have a stable presidency - it is just good sense. When you have a rotating presidency every six months, nothing happens," he said in an interview on BBC Radio 4's Today programme.
Mr Giscard's comments were echoed on the Radio 4 World at One programme by Polish Europe Minister Jaroslaw Pietras, who said he was disappointed at the lack of progress towards resolving a dispute over the EU budget.
UK Europe Minister Douglas Alexander said London was working hard to make progress on both questions - the future of Europe and the framework budget for 2007-13.
"On the future of Europe, the prime minister was very clear that the right response was not to have further institutional discussions at this stage, but actually to have a broader debate about the future of Europe," he said.
Douglas Alexander: October meeting will look at 'big challenges'
He said much was being done to prepare for a meeting of EU leaders in London next month where "a more strategic view" would be taken of the bigger challenges facing Europe.
On the EU budget, he said the UK had held bilateral meetings with all the other 24 member states, which would help British officials judge whether a deal could be done this year.
If it could, he said, the "right place" for this would be a summit in Brussels in December.
Mr Giscard d'Estaing's comments came a day after the President of the European Commission, Jose Manuel Barroso, called on the EU not to get bogged down on the issue of institutional reform because there would be no constitution for "at least two or three years".
The former French president told the BBC he thought France would re-open the constitution debate after its 2007 election and that the document would ultimately be approved.