Felixstowe gained government approval early in 2006 but one condition was that work could not start on phase one until all agreements were in place for necessary rail upgrade works, although the rail works themselves are not required until phase two.

However, there was another public inquiry into the proposed rail works last year and delays in drawing up the agreements continue.

A statement from the council said changes to the scheme’s timing were requested because of “changing market conditions and the threat of expanding competing ports”.

The port has agreed to bring forward some of the required road improvements in return for the variation.

“It is clear that to remain competitive, the Port of Felixstowe must soon increase its capacity. I am pleased that this council has been able to support its goal and so promote the future prosperity of the port, its employees, associated industries and the local economy generally,” said councillor Colin Hart, cabinet member for economic development.

FSR will create 1,350 metres of quay dredged to 16 metres alongside, providing 1.5m teu capacity.