Despite growing pressure from the United States, the European Union maintained a united front yesterday over its determination to ban the merger between Boeing and McDonnell Douglas. The senior aides of the 20 commissioners that make up the EU executive were expected to endorse late last night the draft decision to prohibit the deal on the grounds that it would harm fair competition in Europe, sources close to the negotiations said.

They said Boeing had not made any new proposals since Tuesday to try and head off a ban by meeting Commission concerns about such things as Boeing's market share and the impact of exclusive sales agreements with major airlines.

Senior Commission officials dealing with competition matters, meeting on Thursday evening, had already unanimously backed the proposal by the executive's merger task force to block the deal.

A final decision is expected to be made by the commissioners at their regular meeting next Wednesday.

Competition Commissioner, Mr Karel Van Miert, who has ferociously opposed the merger from the start, needs only a simple majority in the Commission for the decision to be approved.

A last-minute agreement was still possible although unlikely, as pressure increases on the other side of the Atlantic and the Europeans refuse to soften their position, the sources said.

They said American lobbying was intensifying in the EU's larger states, particularly Britain whose special relationship with the US has been given fresh impetus by Labour's Mr Tony Blair taking over as British Prime Minister.

"Britain is under very strong pressure and so are France, Italy and Germany," an EU diplomat said.

A spokesman for Britain's Department of Trade and Industry said the department did not have a position on the merger, adding it was a matter for the Commission.

US President, Mr Bill Clinton on Thursday raised the possibility that the United States may go to the World Trade Organisation or impose sanctions on Europe if it blocks the $14 billion (£9.3 billion) merger, but said a trade war could probably be avoided.

On the European side, French President, Mr Jacques Chirac, argued the deal was "extremely dangerous" for Europe and expressed concern that some of his partners in the 15-nation bloc would not resist the pressure coming from the US.

German Chancellor, Dr Helmut Kohl weighed in yesterday, urging European aerospace firms to consolidate in response to the competitive threat from the planned merger.

"I think that Europe must give a very clear answer to the American challenge in the aerospace sector by founding its own large concern," Dr Kohl told a news conference.