It emerged yesterday that Mr Byatt, who is in charge of financing for large companies at NatWest, has suggested to Sir Alastair a number of times in recent months that he should quit. He believes Sir Alastair has become a blockage in negotiations on restructuring the company's pounds 8.1bn of debts.
The decision by NatWest to turn against Sir Alastair is significant because the bank was a leading force behind the original plans to build the Channel tunnel. As one of four agent banks acting as a co-ordinator for the 225- strong bank lending syndicates it is one of the most influential organisations in the affair.
This gives it proportionately much greater influence than its pounds 250m loans to Eurotunnel - 3 per cent of the total - and gives weight to its decision to line up against Sir Alastair ahead of the first formal round of debt reconstruction talks. However, there was deep confusion yesterday about how much outside support Mr Byatt and NatWest have gathered among the rest of the syndicates.
One source close to the row minimised the extent of support among the banks for the NatWest position and described it as part of a softening- up process ahead of a meeting between Eurotunnel and the steering group of bankers.
This key meeting, the first formal talks on debt reconstruction proposals, is planned for an as yet unspecified date between 5 and 15 May but there has been no confirmation yet that it will go ahead.
One source said NatWest might have the support of a second influential British bank but it was unclear last night whether this was Midland, the fourth commercial bank in the steering group.
The banks have been blaming late information from Eurotunnel for the delay in getting down to formal negotiations while Eurotunnel has been blaming rows among the banks on the shape of the debt reconstruction plan.
A banking source also confirmed claims that the NatWest line on removing Sir Alastair is not supported by either Credit Lyonnais or Banque Nationale de Paris, the two influential French banks on the steering group handling negotiations.
The long-simmering row over whether Sir Alastair should be forced out to pave the way for a debt rescheduling was discussed at a meeting of the banks' steering group in Paris on Sunday, the latest in a weekly series of meetings held alternately in London and Paris.
The French are claimed by sources close to the dispute to have no plans for pressing for the removal of Sir Alastair's French co-chairman, Patrick Ponsolle. The banks have no direct way of forcing Sir Alastair out and would have to rely on behind-the-scenes pressure on the Eurotunnel board.
He has a contract that runs until October and has made clear in the past that he intends to stay until the negotiations with the banks are complete, although that does not appear to mean staying until all 225 members of the syndicates have voted in favour - which may be well into next year.
Suggestions negotiations will be far enough advanced for Sir Alastair to step down at the annual meeting in June are said to be unrealistic because talks are more likely to drag on until the autumn. NatWest is said to have become increasingly concerned that Sir Alastair's combative manner and his stout defence of the rights of shareholders is proving counterproductive - especially since he made clear in public that the Eurotunnel board was prepared to fight the banks under French law, which is more sympathetic than English law to the rights of shareholders against banks creditors.
In France, there has been widespread criticism of the banks on the grounds that they have long been effectively in control of Eurotunnel and are therefore responsible for the plight of shareholders, the great majority of whom are French. John Melbourn, a senior main board director of NatWest, and Mr Byatt are believed to have been strong supporters of Sir Alastair as the best man to force through the project during the construction phase. But the view has emerged since Eurotunnel suspended interest payments on its junior bank debt last September that it is now time for him to move on.
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