The chair of the European Parliament's economic and monetary committee, Sharon Bowles, has criticised some of her colleagues for ignoring the markets.
Ms Bowles chaired the session on Monday about the eurozone debt crisis.
"Jean-Charles Juncker, the president of the Eurogroup... said, 'We shouldn't believe the markets,' and he got big applause," she told BBC News.
She added that the big problem was that politicians thought the markets would do nothing while they went on holiday.
"It was a little bit of playing to the crowd, but that is the attitude amongst many who who think politics is above the markets and politics has to dictate," she said.
A second bailout for Greece was agreed on 21 July, but will not be implemented by eurozone parliaments until mid-September.
"We had the rather awkward situation that the political world expected the markets to sit on their hands for a few weeks while everybody was on holiday," Ms Bowles said.
There have been hefty falls on global stock markets during August.
At Monday's session, European Central Bank president Jean-Claude Trichet said, "The full and timely implementation of the July 21 agreement between heads of state or government is of the essence."
His comments mirrored those of European Commission President Jose Manuel Barroso, who called for quick implementation in early August, despite European parliaments being on summer breaks.
"The problem with the latest package is that some of it has to be approved by national parliaments and we had the situation that everybody was on holiday, and in particular it has to be approved by the German parliament and they won't be doing that until sometime in September," said Ms Bowles, who is the Liberal Democrat member of the European parliament for the South East of England.