It is understood that Mr Montague's other main personal bankers, Commerzbank and Barclays, have dropped proposals for Mr Montague to apply for an individual voluntary arrangement, a less punitive alternative to bankruptcy, and are backing Royal Bank.
Meanwhile two of the biggest lenders to Tiphook, National Westminster and Commerzbank, have been drawn into a US class action against the company and some of its directors alleging that investors were misled during the issue of the bonds in 1992 and 1993 before the emergence of commercial problems at the group. The lawsuit claims the banks helped to mislead investors.
Also named as defendants are two former Tiphook non-executive directors, Sir Charles Powell, now a non-executive at NatWest, and Martin Kohlhausen, chairman of Commerzbank, as representatives of the banks.
The bankruptcy petition from Royal Bank was made public by a representative of American bondholders at last month's Tiphook annual meeting. Tiphook renamed itself Central Transport Rental Group at the meeting.
The bulk of Mr Montague's personal loans are from Commerzbank, while Barclays has a mortgage over his pounds 8m Oxfordshire estate.
Mr Montague still has a chance to forestall the bankruptcy hearing by making a proposal to the court before 28 October for settling his debts.