London Mayor Boris Johnson leaves with his wife Marina Wheeler, left, after casting his vote in Islington, London. (STEFAN WERMUTH/Reuters)

Britons voted Thursday in a spate of local and mayoral elections, including in London, where voters turned out to choose the mayor who will run the city as it hosts this summer’s Olympic Games.

In the capital, the main battle is between incumbent Boris Johnson, a Conservative, and Ken Livingstone, a maverick Labor politician who served as London’s first elected mayor between 2000 and 2008. His predecessors were not directly elected.

If the polls are right, Johnson, a charismatic politician who is popular in spite of — or perhaps because of — his many gaffes, is on course to defeat Livingstone, whose campaign has struggled to regain steam following accusations of tax avoidance.

A Johnson win would be a welcome boost for Prime Minister David Cameron’s Conservative-led government, which has been dogged by plummeting polls and a string of political setbacks, including an ongoing scandal over links with Rupert Murdoch’s News Corp.

Cameron’s party is bracing for dismal results in local elections nationwide, with almost 5,000 seats up for grabs in 181 local authorities across England, Scotland and Wales.

Voters are expected to punish the coalition government for a run of grim headlines in recent weeks, including the botched handling of a fuel strike, a failed attempt to deport a radical cleric and a hike in taxes on pensioners and on the sale of hot snacks.

The recent news that Britain has slipped back into recession has also added to the woes of a government whose key pledge is to turn around the economy.

American-style city mayors are a relatively new phenomenon in Britain. In 2000, London became the first city in the country to directly elect a mayor. 

Most cities here are run by local councils, with the leader chosen by other councillors. But spurred on by the government’s enthusiasm for localism, the appetite for a directly elected boss of a city could be changing. 

Ten cities in Britain, including Birmingham and Manchester, held referendums Thursday on whether to adopt direct election of mayors, while residents of Liverpool and Salford voted for their first elected mayor.

Most results are expected Friday.