Arriva said punctuality was a challenge on the Cambrian Line

Montgomeryshire MP Lembit �pik said he has written to Arriva Trains following a "steady stream" of criticism.

Mr �pik, leader of the Welsh Liberal Democrats, said delayed trains were "disrupting people's working lives".

Arriva blamed the "limitations" on the single track rail line but said it was working to improve passenger services.

Mr �pik added:"This is appalling service. Local people have jobs to do and Arriva Trains Wales is providing a shocking service."

Eleanor Cruse, who travels by train daily from Newtown to Shrewsbury and who is among those to have complained to the MP, said it was common for her to arrive late for work.

When we are being encouraged to use more public transport, this isn't a very good advert. Passenger Eleanor Cruse

She said in the last three weeks she had arrived on time for work at a bank just twice.

"The train is supposed to leave Newtown at 8.40am, but it can be up to 20 minutes late," said Mrs Cruse.

"Fortunately, I have an understanding team leader but I don't want to take advantage. If I am late I tend to work during my lunch hour.

"When we are being encouraged to use more public transport, this isn't a very good advert."

The rail company said the ability to deliver a punctual service would always be challenged by the restriction of the Cambrian Line.

Mike Bagshaw, commercial director for Arriva Trains Wales, said there were "inherent problems".

He added: "While we are working with Network Rail to address issues of congestion and lift speed restrictions on the line, the ability to deliver punctual train services will always be challenged by the limitations of the line, which is mainly single track."