The Conservatives have shown themselves to be the "nasty party" with personal attacks on Ed Miliband, according to a new Comres/ITV News poll.
Last week, Defence Secretary Michael Fallon was criticised for claiming that Mr Miliband had "stabbed his brother in the back" to become Labour leader and would do the same to Britain to become Prime Minister.
Forty-six per cent of Britons believed attacks such as this proved the Tories were the "nasty party".
Around half (51%) disagreed with Mr Fallon's statement, saying Mr Miliband's victory over his brother David in the Labour leadership contest in 2010 did not show that he has bad moral character.
The findings also suggested that most Brits believe personal attacks by politicians on their opponents is unnecessary in trying to win their votes.
The Conservatives were also judged to be running a more "dirty" campaign than Labour.
David Cameron told ITV News last week that his party had no plans to change their campaign strategy amid criticism that attacks on his main rival were too personal.
Despite Mr Miliband's efforts to promote his party's economic credibility in yesterday's manifesto announcement, the Tories remained the most trusted to promote economic growth (39%) and reduce the deficit (43%).
Labour were judged to be the most trusted party to manage the NHS (37%), leading the Tories by 13 points.
Some 49% of Brits believed the health service should be the biggest priority for the Government, with immigration in second place on 44%.
Other key findings from the poll include:
ComRes interviewed 2,036 British adults online between April 10 and 12 as part of the poll, just days before Labour and the Conservatives launched their election manifestos.