(Reuters) - Britain's opposition Labour Party has a one percentage point lead over Prime Minister David Cameron's Conservatives, according to a YouGov opinion poll for the Sun newspaper published on Tuesday.
The two main parties have been neck-and-neck in most opinion polls since the start of the year, with neither establishing a sustained lead exceeding the 3-point margin of error.
The poll ahead of the May 7 election showed Conservatives at 34 percent, down one point from Monday, versus Labour at 35 percent, up one point, polling company YouGov said.
Opinion polls have consistently shown that neither of the two main parties is likely to win an overall majority in the 650-seat Parliament.
Reporting by Shivam Srivastava in Bengaluru; Editing by Cynthia Osterman