CONCERN is growing over delayed plans for a £40m rail freight upgrade between Southampton's docks and the Midlands.

Britain's business chief, Digby Jones, is the latest prominent public figure to express frustration at the sheer lack of progress.

The director-general of the influential Confederation of Business Industry today hit out at the government over the traffic-reducing project.

He said: "Some civil servant somewhere has put that at the bottom of the list. Transport has been on the back-burner for a year but it has to come back on the radar screen."

The rail freight upgrade would see tracks lowered to allow the new generation of super-sized 9ft 6in containers to pass under bridges and through tunnels in Hampshire.

According to transport experts, one freight train carries the equivalent of up to 75 lorry loads, reducing road congestion and pollution levels.

A similar project between Felixstowe and the Midlands, costing nearly £30m and involving work at 31 key locations over 18 months, was officially opened last month.

Southampton and Felixstowe are strategically important because they are the UK's top two deep-sea container ports.

Southampton relies on containers being transported by lorries to the rest of Britain along already clogged roads like the M271, M27, M3, A34 and M40.

That situation has fuelled worries that the city, which has an estimated 10,000 people involved in port-related work, will be left behind economically if fed-up shippers take their custom elsewhere.

Port bosses have already warned that the government's rejection earlier this year of controversial plans for a £600m container port at Southampton Water's Dibden Bay, on environmental grounds, will affect trade because storage space is running out.

Leaders in the regional commercial and political sectors say the rail freight upgrade would help safeguard the docks' future.

Any work would be undertaken by infrastructure owner Network Rail on the advice of the Strategic Rail Authority (SRA).

The SRA has already published a commitment to the upgrading, and it is main plank of the government's regional transport strategy.

Brad Roynon, the chief executive of Southampton City Council, has thrown his weight behind calls for the enhancement.

Fearing a delay due to lack of funding, he wrote to SRA boss Nick Newton and transport minister Tony McNulty, asking for a progress report.

Mr Roynon told them: "I am sure you will appreciate these are serious concerns for the sub region and that to find them arising so soon after the Dibden Bay Inquiry decision is causing significant disquiet."

Andrew Kent, the director of ABP in Southampton, which owns the port, said pressure is being brought to bear on the government from many port users.

He added: "We agree with what Digby is saying. The government must commit to that investment, but it hasn't done so."

SRA spokesman Jonty Alone said: "We believe there is a sound business case for the rail freight upgrade between Southampton and the West Midlands.

"In conjunction with the Department for Transport, the SRA is assessing the order of priorities for this scheme, alongside other rail projects with similarly sound business cases."

The SRA declined to be drawn on any of the criticisms.

Southampton last year received more than 1.38 million containers, of which 360,000 were 9ft 6in containers - nearly 29 per cent of total throughput. By comparison, Felixstowe received 1.7m containers, a quarter of which were bigger ones, as opposed to the previously standard 8ft 6in size.