THE Liberal Democrats have vowed to “deliver” an ambitious strategy to transform Northern rail links - despite its multi-billion pound price tag.

Nick Clegg’s party also promised “devolution on demand” for local authorities, a legal right to force Whitehall departments to hand down new powers.

And it paved the way for bigger council tax rises, by calling for the axing of the requirement for town halls to win a referendum before bills go up above a certain level – currently two per cent.

The policies were unveiled at a London manifesto launch at which Mr Clegg urged voters to give him – not the “extremist” SNP, or UKIP – the balance of power on May 7.

The deputy Prime Minister said: “Do you want Nigel Farage walking through the door of No 10? Do you want Alex Salmond sat at the Cabinet table? Or do you want the Liberal Democrats?

“The Liberal Democrats will add a heart to a Conservative government and we will add a brain to a Labour one."

The other main manifesto pledges were to:

* Increase the education budget to £55bn by 2020 - £5bn a year more than promised by the Tories and £2.5bn more than Labour.

* Invest £8bn in the NHS, with equal care for mental and physical health.

* Pass five new laws to protect nature and fight climate change.

* Balance the budget “fairly”, through a mixture of cuts and taxes on higher earners.

On transport, the document went further than either Labour or the Conservatives by saying: “We will deliver the Transport for the North strategy to promote growth, innovation and prosperity.”

But that strategy – with ten proposed new, or upgraded, rail links – must first be whittled down from costing an eye-popping £77bn, when unveiled last month.

In contrast, Labour pledged only to “expand rail links across the North”, while the Tories are committed only to “developing” a fast Trans-Pennine link – so-called HS3.

The Lib Dems also ruled out cutting the number of MPs, as the Conservatives want, without proportional representation for Westminster, but with no mention of a referendum to approve it.

Locally, the party's Bradford East candidate David Ward was bullish about his chances of hanging on to his seat in next month's election, despite the Lib Dems polling at about eight per cent nationally.

He said: "Eight per cent is a national opinion poll on 'Who would you vote for if there was a general election tomorrow?'.

"When people polling in my constituency ask, 'Are you going to vote for David Ward?, it is a completely different story.

"We all know that Liberal Democrat MPs actually hold on to their seats better than other parties. That has always been the case."