David Cameron rolled into the Eastleigh by-election today as he attempted to bolster the campaign to get Maria Hutchings elected.

Mr Cameron, fresh off the plane from a trade visit to India, was with Tory candidate Maria Hutchings when they visited Prysmian Cables & Systems in the Hampshire constituency and he opened a new £2 million high voltage lab.

A week from polling day in the by-election triggered by disgraced Chris Huhne's resignation, the Prime Minister took questions from an audience of workers on topics such as Europe, VAT, immigration and benefits.

On the topic of handouts Mr Cameron shared the frustration of one man who complained that alcoholics get more money and if they did not they would not be alcoholics.

Mr Cameron joked: ''I think I have found my next welfare minister here.

''It drives people mad to know that they are working hard, paying their taxes and yet they can see someone on the same street as them swinging the lead,'' he said.

He explained that the Government is now ensuring that work will always pay more than benefits.

The by-election contest, pitting the Tory and Lib Dem coalition partners against each other, is seen as a key test for Mr Cameron in the kind of seat his party needs to win if he is to get an outright majority in the next general election.

Both parties have thrown themselves into the contest, with a string of ministers and high-profile figures filing down to Eastleigh to campaign, but there have been signs that the Lib Dems - who have a strong council presence in the area - have mobilised most effectively so far.

It is believed they have a strong lead in postal votes giving the Tories a mountain to climb on election day.

Meanwhile, Labour candidate John O'Farrell was campaigning with shadow education secretary Stephen Twigg at a day nursery in Eastleigh.

The by-election on February 28 was called after Huhne resigned upon admitting he perverted the course of justice. Huhne - who faces prison when he is sentenced - held the seat for the Lib Dems at the 2010 general election with a relatively small majority of 3,864.