LONDON, July 31 (Reuters) - John Lewis [JLP.UL], the employee-owned group viewed as a barometer of British retail spending, posted a big rise in weekly sales at its department stores, boosted by a strong end to its stock clearance sale.

A John Lewis worker and customer - Photo: www.johnlewispartnership.co.uk

The group, which also runs the upmarket Waitrose grocery chain, said on Friday 31 July sales at its 27 department stores rose 6.3 percent year-on-year to 48.65 million pounds ($80.5 million) in the week ended July 25.

That followed a 5.3 percent increase the week before.

Global Insight economist Howard Archer described the result as "impressive and encouraging".

"With sharply reduced mortgage payments, lower utility bills and generally increased discounting boosting purchasing power, it seems that a good many people are currently more able and willing to step up their discretionary spending," he said.

A string of British retailers, from home improvements group Kingfisher (KGF.L) and fashion chain Next (NXT.L) to grocer Morrison (MRW.L) and bicycles specialist Halfords (HFD.L), have reported better-than-expected trading in recent weeks, raising hopes of a rapid recovery from recession.

However, many remain cautious as unemployment is still climbing and VAT sales tax, mortgage rates and taxes are all likely rise next year.

Asda Chief Executive Andy Bond told Reuters on Wednesday 29 July that retailers faced a "long, slow recovery."

"We believe that the upside for consumer spending is likely to remain limited for some time to come," Archer said.

John Lewis said weekly fashion sales jumped 12.5 percent year-on-year, while sales of home-related products rose 4 percent and sales of electricals and home technology were up 2.9 percent.

Sales at Waitrose, which runs 213 stores, climbed 9.9 percent year-on-year to 83 million pounds.

($1=.6045 Pound)

(Reporting by Mark Potter; Editing by Hans Peters)