Britain’s economy recorded its fastest annual growth since 2007 last year despite a bigger-than-expected slowdown in the final three months of 2014, giving a mixed message just 100 days before Britons go to the polls.

British gross domestic product grew by 2.6 per cent in 2014 as a whole, the Office for National Statistics said yesterday, up from 1.7 per cent in 2013 and putting it on track to have been the world’s fastest-growing major advanced economy last year.

While most countries have not yet reported 2014 growth data, Britain’s reading places it ahead of International Monetary Fund estimates for other big developed economies last year, a fillip for British Prime Minister David Cameron before a national election on May 7.

But a bigger question looms as to whether 2014’s growth marks a temporary high point as the economy finally started to rebound strongly after years of sub-par growth following the financial crisis, or if it is part of a longer expansion.

The IMF forecasts growth of 2.7 per cent for this year, though economists polled by Reuters on average predict a slight slowdown to 2.4 per cent.

Yesterday’s data showed some loss of momentum, as growth in the last three months of 2014 fell to 0.5 per cent from 0.7 per cent in the third quarter of the year, a sharper slowdown than the 0.6 per cent growth most private-sector economists had expected.

But the ONS’s chief economist, Joe Grice, said it was “too early to say” if this slowdown would persist.

“The dominant services sector remains buoyant while the contraction has taken place in industries like construction, mining and energy supply, which can be erratic,” he said.

Services output grew by 0.8 per cent on the quarter, the same rate as in the third quarter, but overall GDP growth was held back by the biggest quarterly falls in construction and industrial output since 2012.

Weaker gas and electricity generation dragged on industrial output – possibly linked to slightly warmer-than-usual weather over some of the quarter. The retail sector was a major driver of services growth, adding to signs that Britain’s recovery remains more reliant on consumers than had earlier been thought.

In the immediate future there will be further support to household demand from the sharp drop in oil prices, which are now less than half their level in the middle of last year.

Britain’s economy is now 3.4 per cent larger than its peak before the financial crisis, and about 8 per cent bigger than when Cameron’s Conservative-led coalition came to power in May 2010.

But much of this has been driven by a higher population, and output per head is still below pre-crisis levels, despite unemployment at a six-year low of 5.8 per cent.

Wages remain below pre-crisis levels in real terms and only now are they starting to grow faster than inflation, prompting the opposition Labour party to continue to focus on a “cost-of-living crisis” in the run-up to the election.

The ONS’s preliminary estimates of GDP are among the first in the European Union, and are based partly on estimated data. On average, they are revised by 0.1-0.2 percentage points up or down by the time a third estimate is published two months later.