British lenders approved the highest number of mortgages in more than five years in November but business lending slumped, Bank of England data showed on Friday, raising doubts about the sustainability of growth.

Britain’s economy enjoyed some of the fastest growth of any major industrialized economy in the first nine months of 2013, and a strong fourth-quarter gross domestic product reading later this month could put it on track for its best year since 2007.

But growth has been largely driven by the consumer sector, and the Bank of England has warned that exports and business investment will need to strengthen in 2014 for growth to last.

Friday’s data confirmed a revival in the housing market, with 70,758 mortgages approved in November, up from October’s 68,029, the greatest number since January 2008 and beating economists’ average forecast of a rise to 69,000.

But net business lending tumbled by 4.7 billion pounds in November, the biggest drop since the data series started in April 2011 and one which leaves lending 3.9 percent lower than a year earlier.

The BoE had no immediate explanation for the fall, other than that it was concentrated in larger firms. Lending to small businesses rose marginally.

The central bank figures follow news from mortgage lender Nationwide earlier on Friday that house prices rose in December at their fastest annual pace in over three years – increasing by 8.4 percent – and come alongside a construction industry survey that reported some of the fastest growth since 2007.

The Markit construction PMI data reported that house-building remained the fastest-growing sector of the construction industry in December, though commercial work also picked up.

Mortgage approvals in November will have received a modest boost from October’s expansion of the government’s Help to Buy Scheme to insure lenders against the risk of giving mortgages to borrowers with deposits of as low as 5 percent of a house price.

Prime Minister David Cameron said on Thursday that the scheme had led to an extra 6,000 mortgage applications between October and December.

However the program has been criticized by the opposition Labour Party and many economists as risking simply pushing up house prices, rather than increasing house-building.

Mortgage lending has also been boosted by the BoE’s Funding for Lending Scheme, which started in August 2012, though late in November the central bank said that from 2014 the scheme would be restricted to offering cheap finance for business lending.

Source: Reuters (Reporting by David Milliken and Alexander Winning)