Oldham vote: By-election victory just the first step for Labour says Miliband

The Prime Minister was forced to deny giving the Liberal Democrats an easy ride to stop them suffering a humiliating collapse in support amid concern from Tory activists that their own campaign had been lacklustre.

Although some coalition enthusiasts have suggested agreements between the two parties when fighting elections to maximise the chances of beating Labour, former Tory MP Paul Goodman, now executive editor of grassroots website Conservative Home, insisted that the party must "fight to win" in future by-elections.

The unease comes after Labour's Debbie Abrahams comfortably won the by-election with 14,718 votes, ahead of the Lib Dem Elwyn Watkins with 11,160. Tory Kashif Ali was third with 4,481 as support for the Conservatives fell away sharply.

Although the result was disappointing for the Lib Dems – who had forced the contest after a successful legal challenge to the General Election result, claiming the Labour opponent Phil Woolas had lied about Mr Watkins – they were still relieved that support did not collapse altogether after abandoning their pledge to oppose any increase in university tuition fees and the coalition spending cuts.

Mr Miliband, the Doncaster North MP, will hope the result will bolster his position after a mixed start as Labour leader.

"This is a first step in a long journey for Labour but, more importantly, I hope the Government will listen to what they've said about these key issues," he said.

"They said to the Government, think again on VAT, think again on the trebling of tuition fees, think again on the police cuts that are going to affect their communities.

"And I think part of what it should be about in this country is listening to the voters. I think that's what David Cameron and Nick Clegg should do."

Mr Cameron insisted he was "proud" of the Conservative campaign, despite seeing his party finish a distant third while the Lib Dems were unable to overturn a wafer-thin Labour majority.

"I was one of the first Prime Ministers for many, many years to campaign personally in an English by-election. I enjoyed doing that. I am proud of the campaign we fought," he said.

But Mr Goodman said: "The Prime Minister should also now distance his party from the Liberal Democrats. Conservative backbenchers and party members alike want to see it retain its own distinct identity, and a sense that Liberal Democrat concerns are more important to Downing Street than their own helps to explain, at least in part, recent rebellions and discontent, and hence the Government working less effectively than it might."

He added: "In future, the party should fight by-elections to win. It was never likely to win Oldham East and Saddleworth. But the lack of an enthusiastic start made such an outcome certain, and the repercussions of Downing Street's determination to pull CCHQ's campaigning punches have been damaging."

Mr Cameron, visiting Newcastle, also insisted that the Tories had fought a "good campaign". He added: "Of course, we started in third place and we ended in third place. That is often the way with by-elections. This was not an unexpected result."

Lib Dem leader Nick Clegg, who made three campaign visits to the constituency, claimed it had been a "strong result" for his party, saying that he had always expected a "very close race" with Labour.

Man held after protest at PM's visit

Police arrested a protester after a demonstration as Prime Minister David Cameron's motorcade left Newcastle's Centre for Life on a visit yesterday.

Students had found out Mr Cameron was at the science centre and around 50 began chanting as he left, with some running into the street as the official motorcade left.

Mr Cameron visited the Centre for Life to discuss how innovation can boost growth. He watched as scientists researched stem cells and listened as they explained how their expertise was used to save sight.

Afterwards, he said: "Our policies are going to expand the private sector. I am standing here in a science lab in Newcastle where they are creating wealth, jobs and inventions of the future."

A spokesman for the demonstrators claimed it was a "peaceful protest" and wanted to "express our outrage".

A Northumbria Police spokesman said: "Police attempted to facilitate a peaceful protest; however, during the demonstration, a 19-year-old man was arrested on suspicion of criminal damage after a police vehicle sustained minor damage."