Plans have already been drawn up to request extra negotiating time, but the companies are unwilling to release pressure by deploying them until they have some real political progress to show British regulators, banking sources said.

People close to the talks said Britain appeared most open to the deal, Germany was the least keen and France wanted more time to think it over. Yet as problems pile up, all sides have moved to deflect the responsibility in case the talks break down.

Despite the negative atmosphere left by Friday’s press briefings, industry experts say it is too early to say whether the merger will happen but note the parties are used to negotiating down to the wire.

EADS was created from a merger in 2000 only after talks between France and Germany broke down and the plan collapsed, bringing the two sides back together to negotiate a complex shareholder pact limiting the role of the French state.

However, those negotiations were held in secrecy while a blizzard of publicity surrounding the latest talks has brought pressure from investors and unleashed new negotiating demands.

BAE’s top shareholder Invesco Perpetual blasted the proposed deal on Monday, citing state interference, poor terms and a lack of strategic rationale. The investment company, which has 13 percent of BAE, is reported to have clashed in private with BAE leaders as soon as the talks surfaced last month.

BAE shares dipped 1 percent. EADS was fractionally lower.

SOVEREIGNTY

In order to improve the chances of winning approval in the United States, Britain wants France to commit in writing to forego any future increases in its shareholding, which would start out at 9 percent under a proposed 60:40 split between EADS and BAE.