More than 100 London Midland Saturday train services are expected to be cancelled or delayed due to an ongoing driver shortage.
The BBC reports that more than 60 services were expected to be cancelled, with nearly 40 others starting later or terminating early.
London Midland has listed the planned cancellations on its website, which mainly affects services in the West Midlands.
It has apologised and said it had seen a higher than normal turnover of drivers.
Lines affected include Birmingham-London, Birmingham-Liverpool, Birmingham-Coventry-Northampton, Lichfield-Birmingham-Redditch and Wolverhampton-Birmingham-Walsall-Rugeley.
A London Midland spokeswoman told the BBC that the firm was 'really sorry' and was working hard to resolve the problem.
She said it was making 'significant' progress and that many drivers were working on their days off.
'On Sunday and Monday we expect very few services to be affected, probably about six on each day,' she said.
Since 7 October, the firm has cancelled more than 470 trains with others disrupted. The company runs 1,300 services each day.
Phil Davis, of passenger group Travel Watch West Midlands, said: 'The situation seems to be getting worse and it calls into question the competence of London Midland.'
Mr Davis, a Labour councillor for Birmingham City Council, said he would be writing to the rail regulator.
London Midland said the shortfall in qualified drivers would be addressed by mid-December and says it plans to list its cancellations every day on its website until 11 December.
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