The FTSE 100 <.FTSE> ended up 1.1 percent at 7,089.77 points, its highest ever closing level. It had earlier set an intraday record high of 7,095.36 points, beating its earlier all-time peak of 7,065 points from March.

Uncertainty before next month's British election has weakened sterling , but the benchmark UK stock market has continued to push higher and is up around 8 percent since the start of 2015.

Sterling got another knock after weaker-than-expected UK industrial data on Friday, but equity traders said a weak pound could help British exporters and that individual companies were still seeing a lot of positive developments.

Shire shares rose 5 percent, the biggest gain on the FTSE 100, from a U.S. Food & Drug Administration decision to grant a priority review to its application for lifitegrast, a dry-eye disease treatment.

Homebuilders Barratt Developments and Taylor Wimpey rose, as did property-listing company Zoopla, a day after data pointed to a rebound in British house-price growth in March.

"Whatever form a new British coalition government takes, the UK still has a massive need to build more homes," said Charles Hanover Investments' partner Dafydd Davies.

ITV AT 15-YEAR HIGH

Media company ITV hit a 15-year high after investment bank Morgan Stanley raised its price target on the stock.

However, some mining stocks including Anglo American and Rio Tinto slipped, hit by a renewed slide in prices for iron ore.

Drugmaker AstraZeneca also fell after a negative review for Astra's diabetes drug Onglyza.

Neither Prime Minister David Cameron's Conservatives nor Ed Miliband's Labour Party have a clear lead in the polls, while a possible referendum on Britain's EU membership, promised by the Conservatives, is adding to nervousness among investors.

Yet Richard Buxton, head of UK equities at Old Mutual Global Investors, said he was making no short-term portfolio changes and sticking to financial and cyclical stocks.

Beaufort Securities sales trader Basil Petrides, however, was adopting a more cautious attitude.

"I can't buy into the market here. I would rather be taking some money off the table," he said.

(Additional reporting by Lionel Laurent; Editing by Andrew Roche)

By Sudip Kar-Gupta