LONDON (Reuters) - Retailer John Lewis JLP.UL posted a double digit rise in underlying weekly sales as consumers showed they are still prepared to spend despite the prospect of tax rises after next month's general election.

The firm, which is seen as a bellwether of the retail sector but has been outperforming rivals over the last six months, said on Friday 16 April underlying sales at its department stores increased 10 percent in the week to April 10.

"Over the two-week Easter period we saw a great 18 percent uplift. All in all a really good two weeks' trading," said David Barford, director of selling operations.

Total sales at the firm's 28 department stores and one "at home" store rose 0.6 percent to 48.8 million pounds.

This figure reflected one day's less trading this year due to Easter Sunday (April 4), the dampening effect on sales of good weather at the end of the week and the distraction of sporting events such as the Grand National.

British retailers are emerging from a deep recession.

On Tuesday 13 April a British Retail Consortium survey said retail sales jumped at their fastest pace in a year in March although the figures were flattered by the earlier timing of Easter this year.

Over the last week Marks & Spencer (MKS.L), the UK's largest clothing retailer, Debenhams (DEB.L), the UK's second-largest department stores group, and sportswear retailer JD Sports Fashion (JD.L) have all posted better-than-expected results.

"Given a series of recent improved data and survey evidence, it does appear that the UK recovery may be becoming a little more firmly established. Nevertheless, we continue to suspect that the upside for consumer spending will be limited in 2010 as households still face very challenging conditions," said Howard Archer, chief economist at IHS Global Insight.

He highlighted high unemployment, low earnings growth, elevated debt levels, and an expectation of higher taxes as the government takes action to cut the public deficit.

John Lewis also owns the 228-Waitrose supermarket chain.

Here, week to April 10 total sales fell 16.7 percent to 80.0 million pounds.

However, compared to the equivalent Easter period last year, sales were up 10.7 percent, underscoring Waitrose's current position as one of the UK's fastest growing grocers.

(Reporting by James Davey, Editing by Mark Potter)