Rail passengers often have to stand on their daily commute

Early morning commuter services from Barnsley and Sheffield often operated at more than 50% over capacity, campaign group Transport 2000 said.

It said much of the blame must rest with the government which had issued "no growth" franchises for 10 years.

West Yorkshire public transport provider Metro said there had been a "phenomenal" rise in passenger numbers.

It had recently added 12 carriages to its services through a �20m partnership with regional development agency Yorkshire Forward.

MOST OVERCROWDED ROUTES Durham to Newcastle (0759) - 88% Cambridge to London Liverpool Street (0718) - 85% Eccleston Park to Liverpool Lime Street (0753) - 85% Cardiff to Maesteg (1721) - 78% Humphrey Park to Manchester Oxford Road (0814) - 75% Morpeth to Newcastle (0800) - 58% Barnsley to Leeds (0731) - 57% Sheffield to Leeds (0714) - 53% Sutton to Luton (1644) - 50% Northampton to Birmingham New Street (0726) - 45%

"We need to find ways to increase capacity across the network," a Metro spokesman said.

"But when the government put the franchises out, there was no capacity for growth so we will have to continue looking for innovative ways to fund extra rolling stock."

The Transport 2000 survey highlighted the 0731 Barnsley to Leeds service (57% over capacity) and the 0714 Sheffield to Leeds route (53%).

The most-crowded service in the organisation's list is the 0759 Durham to Newcastle service which can operate 88% over capacity.

A Transport 2000 researcher known as Sardine Man will be travelling on some of these identified routes over the next two weeks to gather evidence to send to Transport Secretary Douglas Alexander ahead of the government's expected major rail strategy report this summer.

Julia Thomas, Transport 2000's public transport campaigner, said: "It's very easy to blame rail operators for overcrowding problems, but actually a lot of it is down to the government's rail policy.

"They have issued 'no growth' franchises for the past 10 years and they've been promoting a policy of fare hikes to get people to travel off-peak, but passengers really don't have that much flexibility.