Chancellor Alastair Darling has told rail operator First Great Western to "get a grip" or risk putting its franchise in danger.

Mr Darling criticised the company while on a ministerial visit to Bristol yesterday.

The Chancellor said: "I know there have been very great problems with this particular franchise that have gone on far too long.

"Frankly, the travelling public using the line are entitled to expect far better reliability and punctuality in a far better service."

Zahra Akkerhuys, a spokesman for passenger group Ox Rail Action, said: "FGW should be extremely concerned by the Chancellor's comments.

"Poor time-keeping continues to be the primary problem from Oxford now."

A spokesman for the rail company said: "First Great Western is investing £200m in its franchise and is the only train operator refreshing all its fleet.

"We have doubled our compensation offer in recognition that there have been performance issues and are working hard to improve our services.

"The benefits of our investments are beginning to show and First Great Western's latest performance figure is a punctuality rate of 85 per cent."

The Chancellor's comments came after it emerged that 300 passengers were forced to squeeze into a two-carriage train instead of an eight-carriage train last weekend due to a scheduling error.