PRIME Minister David Cameron has pledged to rid the district of its decrepit Pacer trains in a new deal for passengers.

He has killed a suggestion that the 30-year-old carriages, sometimes used as short-term substitutes for modern locomotives on the Airedale line, could be 'modernised' rather than replaced.

He said: "Bidders for the Northern franchise will be required to propose plans for the removal of Pacers when they submit their bids in 2015. So those trains are going."

The news will delight passengers alarmed by hints that the trains, widely condemned as "cattle trucks", could survive for another decade.

But Mr Cameron also warned that fares on the Northern Rail franchise must rise to pay for the badly-needed upgrade when the new contract starts in 2016.

He said: "In terms of the fares, Northern Rail is the most heavily-subsidised franchise, so we think you've got to get a fair balance between taxpayer and fare payer to lead to these improvements.

"What we want to see is more frequency, more capacity and higher quality – and that will require everybody to play their part."

But James Vasey, chairman of the Bradford Rail Users Group, disputed the claim that rail services in the north enjoy the subsidy – arguing it props up a decaying infrastructure, long starved of investment.

And he said: "Once we get better trains – and more bums on seats – that might reduce the need for such a subsidy anyway.

"But we must see the trains and feel the benefits first, rather than paying extra to travel on the Pacer trains with promises of jam tomorrow."

Confirmation that fares will rise is likely to come next month when the specifications for the new Northern Rail and TransPennine Express franchises are published.

More details on replacing the 90 remaining Pacers could come in a December 3 mini-Budget, which Chancellor George Osborne has already pledged will focus on the north’s poor transport links.

The DfT had said the Pacers could yet be "modernised" because new trains may not be ready for 2020, when they will fall foul of disability discrimination laws.

Mr Cameron's pledge steals a march on both the Liberal Democrats and Labour after Nick Clegg attacked the "decrepit" Pacers – but said he couldn't "wave a magic wand".

Last month, Labour’s then transport spokesman Mary Creagh refused to guarantee the Pacers would be replaced, or to rule out higher local fares in the north.