(Reuters) - Factory activity grew at its fastest rate in over 15 years in April, but lending to consumers, home-buyers and businesses was weak the month before, leaving question marks about the sustainability of recovery.

Financial markets largely shrugged off Tuesday 4 May's data, which came two days before a national election in which the Conservatives look like they might get a slim majority.

While April's purchasing managers' survey showed healthy growth, the Bank of England reported data from the month before showing the sharpest annual fall in M4 lending to non-financial firms since records began in 1997, suggesting manufacturers may struggle to keep up the brisk pace.

The Chartered Institute of Purchasing and Supply/Markit manufacturing PMI rose to 58.0 in April from an upwardly revised 57.3 in March. This was well above the consensus forecast and the highest reading since September 1994, when Britain's economy was also emerging from a deep recession.

"It is another strong print. This time it appears to be led by exports which is hardly surprising after similar robust numbers from Europe and the U.S. and the weaker exchange rate," said Amit Kara, UK economist at UBS.

But, on top of weak growth in lending to manufacturing, March's Bank figures suggested little support for consumer spending or lending for home purchases.

Net lending secured on residential property tumbled to an eight-month low of 318 million pounds in March from 1.848 billion in February, a fraction of the 1.6 billion expected by economists.

Consumer credit was also weak, dropping to 325 million pounds from 578 million, a three-month low and again below a forecast of 400 million pounds.

The Bank of England and economists said that the fall in net lending secured on dwellings was partly due to a lagged effect from the sharp fall in mortgage approvals at the start of the year, caused by unusually snowy weather and the end of a tax break on home purchases.

Mortgage approvals rose roughly in line with forecasts to 48,901 in March from 46,882 in February but are well below the levels of just under 60,000 achieved in late 2009, never mind the levels of over 100,000 seen during the boom.

"The approval numbers seem to have resumed their slow upward grind, but it's still a recovery from well below the recent peak," said Philip Shaw, economist at Investec.

"The softness of the mortgage lending numbers at least in part reflects the softness of approvals figures over the last couple of months," he added.

Nationwide Building Society's monthly house price survey showed a 1 percent rise in April, the same as in March, but the low level of mortgage approvals reinforced some economists' view that the past year's rebound in prices may not last.

STERLING LIFTS ACTIVITY, RAISES PRICES

The detail of the PMI survey showed the weakness of the pound had given exporters a fillip.

New orders rose at their fastest pace in more than six years, helped by the strongest growth in export orders since the series began in 1996.

In a further sign of the strength of demand, firms reported the first increase in backlogs since the series began in 1999. Output growth remained strong and employment rose for the third time in the past four months.

"Manufacturers reported a flying start to the second quarter," said Rob Dobson, senior economist at Markit.

"The feeding through of rapid output growth to job creation is particularly good news, and bodes well for the sustainability of the UK economic recovery."

The survey cited improved global demand and the ongoing weakness of sterling as factors underpinning the rise in export sales. But the weak pound also contributed to a pick-up in price pressures, with input price inflation surging to its highest since August 2008.

"Increased input costs were blamed on widespread raw material price increases, in many cases reflecting exchange rate or supply-chain factors," the survey noted.

Markit said its survey pointed to manufacturing output growing by as much as 2 percent in the latest three months, suggesting the sector will provide a strong contribution to second-quarter gross domestic product.

However, strong readings from the manufacturing PMI survey have not always been matched by official output data, and some economists say that the survey overstates the true picture.

Britain's economy pulled out of recession at the end of 2009 but the recovery slowed in the first three months of this year, hurt by a severe snow disruption and a rise in value-added tax.

While growth is likely to pick up in the next few quarters, headwinds remain, not least from a fiscal squeeze that economists reckon will be the toughest in at least 30 years.

"We expect consumers to provide little support to the recovery as it develops this year," said Hetal Mehta, economist for the Ernst & Young ITEM Club. "The slow turnaround in lending will constrain the economic recovery over the course of 2010."

(Additional reporting by Fiona Shaikh; editing by Jason Webb)