Arriva said new rolling would be introduced in December

Many have been in service for 15 years and according to groups like Passenger Focus they are showing their age.

But Arriva Trains Wales, which operates most of the country's services, said some more modern rolling stock would be introduced in December.

The Welsh Assembly Government said it was also planning more investment.

I always try to put myself in the place of foreign travellers who come to Wales and want a good experience, and I am sorry they are not getting that currently David Williams, North Wales Business Club

Passenger Focus said it was calling for both the train company and the assembly government to make improvements.

Former railway worker Dave Marks, who campaigns for better services on his local line to Blaenau Ffestiniog, Gwynedd, said: "The last time I travelled down to Llandudno Junction a lot of the trim was loose, being held together by lots of sticky tape and [there were] quite shabby interiors.

"It seems to me that this really is not what we should be aiming for."

David Williams, chairman of North Wales Business Club, is a regular rail user and he said the overall image of the service was "not good".

"I always try to put myself in the place of foreign travellers who come to Wales and want a good experience, and I am sorry they are not getting that currently."

Christopher Boulter, who occasionally travels from Flint to Cardiff, claimed passengers were being crammed into carriages "almost like cattle into cattle trucks".

Mike Bagshaw of Arriva Trains Wales said his company could do better, but trains with more leg room and better air conditioning were on the way.

"We are investing in extra rolling stock and doing the right things to improve the quality of the journey for passengers.

"Many passengers from December will see a step change in the quality of our rail stock."

Twelve modern Class 175 trains, currrently with the Trans Pennine service, will replace older rolling stock in the Arriva Trains Wales fleet.

They will be used on the routes between Holyhead and Cardiff, as well as west Wales to Manchester.