Britain's Prime Minister Boris Johnson steps out of the general election campaign trail bus as he campaigns for the general election, in Washington, Britain December 9, 2019. Ben Stansall/Pool via REUTERS

LONDON (Reuters) - British Prime Minister Boris Johnson’s Conservative Party has seen its lead over the opposition Labour Party narrow slightly to six points, according to an opinion poll by ICM for Reuters published ahead of Thursday’s election.

Shortly after two other polling firms showed the Conservatives’ lead had widened, ICM said support for the Conservatives stood at 42%, unchanged from ICM’s previous poll a week ago, while the Labour Party was up one point at 36%.

The six-point lead was narrower than a range of between eight and 15 points in six polls published between Saturday and the early hours of Monday.

The pro-European Union Liberal Democrats were down one point at 12% while the Brexit Party was unchanged at 3%, ICM said.

ICM surveyed 2,011 adults online between Dec. 6 and Dec. 9.

The poll found that 36% of respondents thought a majority in parliament for the Conservative Party would be the best outcome for the country, a big gap over the 23% who felt a majority for Labour would be best.