The statement by FGW managing director Alison Forster, came just hours after Tony Blair spoke out about FGW?s recent problems during Prime Minister?s Questions and after dozens of MPs condemned the company for the poor services across the West, including delays, overcrowding and higher prices.

Bristol and Bath have been at the centre of the problems, after a new timetable was brought in last month.

But FGW insists it has taken steps to alleviate overcrowding problems

On Monday, the More Trains Less Strain group handed out 2,500 fake tickets at Bath Spa station, to present instead of paying the fare.

Campaigners said more than 2,000 passengers refused to buy a ticket and, with Mr Blair joining the row yesterday, Ms Forster was forced to act.

She said: "Firstly I would like to apologise to our customers for not meeting their expectations. Our team has been working hard to implement measures to improve our services.

"It is clear that we under-estimated demand for our train services and too much capacity was removed from the timetable we implemented in December. We have listened to our customers and increased capacity on the worst-affected journeys and are now implementing measures which will further increase capacity.

"Since December these problems were compounded by difficulties with fleet availability and we have leased additional trains to meet timetable needs and will provide further trains to support our reliability recovery programme.

"In the last few days we have started to deliver the correct number of trains for our services.

"With the additional trains and with better reliability from our existing fleet we are already seeing an improvement.

"Our plans will enable this improvement to continue in the coming weeks.

"Following the additional timetable changes we made last week and with additional trains coming in to strengthen our services in the short term, plus the refreshed High Speed Trains about to enter service creating new capacity on commuter flows into London, we believe we will greatly improve the match between available capacity and demand."

Ms Forster said the timetable changes from January 15 increased capacity on morning peak services between Frome, West Wiltshire, Bath and Bristol, and from Oxford, Didcot and Maidenhead to London.

A new £8 million facility in Bristol would bring maintenance of the fleet in-house, and be better for customers, she said.

The apology came after Mr Blair said at Prime Minister's Questions: "I know, obviously as a result of what happened earlier in the week, there's been a great deal of debate about First Western's services in Bristol.

"I am glad that the company has taken some measures to try and address those concerns."

He said the Road Transport Bill, to be published later this year, would improve transport management in cities, including those with passenger transport authorities.

The Prime Minister was replying to Bristol North West Labour MP Doug Naysmith, who said: "Despite increased investment in public transport in recent years, the situation for my constituents who use FirstGroup's disastrous commuter trains and unreliable and expensive buses is dire.

"The abysmal state of public transport in the greater Bristol area would be greatly improved by setting up an integrated transport system, such as is found in areas with a passenger transport executive."

Earlier, furious MPs from all parties lined up in a special Commons debate to denounce FGW over the chaos on its trains.

But Stroud Labour MP David Drew was not able to speak, as his FGW train arrived an hour late into London, which he said was "absolutely typical".

However, colleagues from across the West took part, as well as MPs from Cornwall, the South Coast and the Thames Valley, all areas where passengers are suffering.

Bristol East Labour MP Kerry McCarthy said the service had been "appallingly unreliable" since the December timetable was introduced.

There were delays and overcrowding, many people had to stand all the way, and others could not even get on to their train.

"Yet to add insult to injury they are having to pay more for these services," she said.

FGW had given one excuse after another, and blamed maintenance problems, but she had been told a huge amount of rolling stock was sitting on the sidelines that could be used, she said.

Bath Liberal Democrat MP Don Foster attacked the "ludicrous" fare increases brought in during the problems, which made the Bath to London route one of the most expensive in the world.

And he said the Government must take some of the blame, as its promises on service levels had not been delivered.

But Rail Minister Tom Harris rejected the claims and refused to hold a special trains summit as FGW had accepted responsibility for the performance of the past few weeks.