Here are the latest developments in the story:
David Cameron's Conservatives and Ed Miliband's opposition Labour Party have been neck and neck in opinion polls for months, indicating neither will win enough seats for an outright majority in the 650-seat parliament.
"This race is going to be the closest we have ever seen," Miliband told supporters on the eve of the vote.
The Conservatives portray themselves as the party of jobs and economic recovery, promising to reduce income tax for 30 million people while forcing through further spending cuts to eliminate a budget deficit still running at 5 percent of gross domestic product.
Labour says it would cut the deficit each year, raise income tax for the highest 1 percent of earners and defend the interests of hard-pressed working families and the treasured but financially stretched national health service.
If neither wins an overall majority, talks will begin on Friday with smaller parties in a race to strike deals. That could lead to a formal coalition, like the one Cameron leads with the centrist Liberal Democrats. Or produce a fragile minority government making trade-offs to guarantee support on key votes.
The two main parties are predicted by opinion polls to win about 280 seats each, Nick Clegg's Liberal Democratic party about 30 seats, the rightwing UK Independence Party two or three seats - but playing spoiler for the Conservatives in many more - and the Scottish Nationalist Party is predicted to win almost all the 59 seats in Scotland.
The British Parliament or House of Commons is made up of 650 seats with 326 required for a majority.
In the last elections in 2010, which also presented a hung result, the Tories had 307 and Labour 258. The Liberal Democrats' 57 helped the Tories cobble together a majority.
A survey conducted by BBC Asian Network/ICM has shown that nearly a quarter of the 700,000 Asian voters are yet to make up their minds about the ballot. Another 39 percent said they had decided, but could change their minds before polling day.
Cameron's party has 12 candidates of Indian origin, including Rishi Sunak, son-in-law of Infosys' N.R. Narayana Murthy, contesting from Richmond. Labour is fielding 52 ethnic minority candidates, including Keith Vaz from Leicester East, Virendra Sharma from Southall and Seema Malhotra from Feltham and Heston.
Indian-Origin Leader's Bid To Replace Rishi Sunak As Conservatives Head King Charles III To Set Out UK Government's To-Do List Rishi Sunak Makes Apology Calls To Ex-MPs After UK Election Loss Parents Gave Names Of Interns, Doctors To CBI In Kolkata Horror: Sources How Extreme Weather Is Leading To Rise In Child Marriages In Pakistan Monkeypox Cases Rising: How Worried Should You Be - 10 Points US Warns Iran Faces "Cataclysmic" Consequences If It Strikes Israel 20 Coaches Of Sabarmati Express Train Derail In UP, No Casualties Two Sisters Returning From Court Run Over By Car In UP: Cops Track Latest News Live on NDTV.com and get news updates from India and around the world.