Long-awaited improvements to rail line in south Bucks could slip further down the priority list after the Government announced it is delaying a raft of upgrades nationwide.

Transport Secretary Patrick McLoughlin told Parliament today that an ambitious £38billion project will have to be scaled back due to rising costs and missed deadlines.

Commuters and rail groups have long been calling for tracks on the Marlow to Maidenhead line to be electrified, with a feasibility study currently under way on the route.

But with the Conservative Government deciding to review all future projects, it is uncertain whether any plans to roll electric trains out to Marlow will be adopted in the next round of spending from 2019.

Victoria Bradley from Network Rail, which is responsible for track improvements, said: “The feasibility study is ongoing and will continue while a review takes place over the summer of Network Rail’s projects, as outlined in the Secretary of State’s speech today.

“The current remit of the Great Western Electrification Programme covers the Great Western Main Line from London Paddington to South Wales.

“The Maidenhead to Marlow line is a branch line off the main line and is one of three branch lines being considered for electrification as part of the feasibility study.”

Marlow is still due to receive a "package of upgrades" in a new franchise for First Great Western, announced in March, but electric tracks are not included.

Though not originally part of the Government’s £38billion upgrade, it was hoped electrification for Marlow’s line would be put high on the list for upgrades in the next batch of spending from 2019.

But with planned upgrades on the Midland Mainline and Trans-Pennine now “paused”, it could spell a longer wait for commuters along the route to Maidenhead, which includes Bourne End and Cookham, while existing projects stay on hold.

In his speech, Mr Mcloughlin’s insisted the electrification of the Great Western Line from London to Swansea, which passes through Maidenhead, is still a “top priority”.

The Government has blamed many of the problems on Network Rail, which it says “has not been good enough” at implementing some of the upgrades.

But Network Rail says last year’s announcement was too ambitious.