Alan Donnelly MEP, who as a senior member of the Economic and Monetary Affairs sub-committee grills the ECB president on policy decisions, says: "With the best will in the world, I do not believe the way the ECB is established is sustainable."
Mr Donnelly, a pro-European, is tipped to be the next chairman of the influential sub-committee. He said he was concerned by the "trend of secrecy" at the bank. "I do think we will see a rather different ECB, still independent of the politicians, by 2010."
Speaking at the launch of a major European study by the accountancy firm PricewaterhouseCoopers, Mr Donnelly criticised Wim Duisenberg, the ECB president, for being "too macho". "It would be very helpful if Mr Duisenberg realised he didn't have anything to prove."
Like many City economists, Mr Donnelly argued that the ECB should follow the example set by the US Fed and the Bank of England and publish the minutes of its meetings. He also said Mr Duisenberg should curb the influence of national central bank governors on European interest-rate policy.
His comments came as economists at PwC warned that an overly tight European interest-rate policy could fatally damage manufacturers in the euro zone. PwC said: "With the ECB continuing to take a relatively tough line, the euro might rise sharply against the dollar and the yen, further squeezing European companies. As a result, growth (in the euro zone) might fall to little more than 1 per cent in 1999 and even lower in 2000 as the downward spiral of confidence and spending undermines domestic growth."
Manufacturers in Germany and Italy already face "near-recessionary conditions", PwC warned. If too-tight interest-rate policy and global developments combine to produce a hard landing, this could tip of major European economies - such as Germany - into decline.
On balance, felt Rosemary Radcliffe, PwC chief economist, Europe should avoid a hard landing, but this depended on other factors, including no spillover of problems in Brazil to other regions and continued strong growth in the US.
Miss Radcliffe said business confidence even in vulnerable economies - Germany and Italy - was still substantially above that in the UK. PwC said there was substantial scope for more cuts in UK rates.
Also speaking at the PwC launch, Jacques Lafitte, a key economic advisor to Commissioner Yves-Thibault de Silguy, said he was confident that the ECB would react appropriately to the challenges ahead.