Britain's railways are policed by an underfunded service that lacks the powers required to do the job effectively, MPs have warned.

A report published by the Commons transport committee urged on Friday that funding of the British Transport Police should be considered as part of a review of the rail industry.

The study highlighted the "unwieldy" way in which the service is funded by the tail operating companies.

There were also concerns that budget cuts could see reductions in the number of officers deployed in London.

"It is vital we have an efficient, effective force to keep our rail system safe," the report said.

"The railways are a specialised environment with specialised needs and need a specialised force.

"The force has been rightly expected to demonstrate the same standards and expertise as a county force but it has been left underfunded and without all the tools it needs to carry out its task."

However, there was backing for plans to create a new authority to oversee the BTP's work.

Committee chairman Gwyneth Dunwoody said the underfunding was "ridiculous".

"It is expected to keep in line with Home Office forces but has no automatic access to funding for the many new initiatives brought forward," she said.

"The needs of the British Transport Police were overlooked at privatisation; the force must not be overlooked again in the government's current rail review.

"It is time to ask hard questions about the consequences of the rail industry funding railway policing."