The French have emerged as the main contenders to buy the Port of Dover, following speculation that Prime Minister Gordon Brown could rubber stamp the sale within days.

Nord-pas-de-Calais regional council, which also owns the port of Calais, could bid up to £350 million. The sale of the largest passenger port in the UK and Northern Europe would mark a dramatic reversal in the fortunes of the two towns. Calais was captured by the English under Edward III in 1347, and the occupation lasted for more than two centuries.

The Port of Dover is one of a number of public assets which have been earmarked for privatisation as the Government battles to reduce its £830billion national debt.

Dover is the largest British port and made a profit of £15.1m in 2008. As a state-owned ‘trust port’, all revenues are reinvested. It is now seeking £400m to expand, as it bids to double freight traffic by 2040.

Chief executive Bob Goldfield said: ‘The time is right for the voluntary privatisation of Dover. We want to invest around £400million on a second terminal and need to invest in the existing terminal, but are unable to because of public sector borrowing constraints. We want to throw off the shackles.’

Other major ports were sold off under the 1991 Ports Act, but Dover was retained because of uncertainty over how construction of the Channel Tunnel might affect it.