The Liberal Democrats are forecast to receive 14 percent of the vote, just 1 point ahead of the UK Independence Party (UKIP).
The survey found that for the second time in several weeks, the two leading parties were neck-and-neck among female voters, who previously showed strong support for the Labour.
Many previous opinion polls, including the one conducted by Omnibus in January, indicated that the Labour held a lead over the Conservatives.
UK citizens will elect representatives to sit in the House of Commons, the country's lower house of parliament, for the next five years.
The two major rivals in the upcoming elections are the Conservative Party, headed by British Prime Minister David Cameron, and the Labour party led by Ed Miliband.
The “short” general election campaign in the United Kingdom will officially begin on March 30, after Cameron visits Queen Elizabeth II and asks her to approve the dissolution of the current parliament.
