May 13 - Britain's biggest department store chain John Lewis said revenue fell last week even though fashion sales got a boost from shoppers trying to copy the look of Royal Wedding highlight Pippa Middleton.

John Lewis store in Cardiff

The employee-owned retailer said on Friday its sales fell 1.4 percent year-on-year to 54.3 million pounds ($88.4 million) in the week to May 7 and were down 3.0 percent excluding VAT sales tax.

"Last week was the first real like-for-like week this year, after a first quarter where calendar events, royal weddings and the warmest April on record made it difficult to compare sales," the firm said.

John Lewis said fashion sales were up 4.9 percent year-on-year. "Following the Royal Wedding there was an ongoing 'Pippa effect' in our occasionwear section, with long, flowing, green and champagne-coloured dresses sought after, delivering the highest sales for this department in four years," it said.

Pippa Middleton arrives at Westminster Abbey before the royal wedding

However, the robust performance in fashion was offset by a 5.6 percent sales fall in the home category and a 3.3 percent decline in electricals and home technology.

British consumers are grappling with government job and welfare cuts, inflation, muted wage growth, a stagnant housing market and the prospect of higher interest rates.

An industry survey on Tuesday said British retail sales surged at their fastest annual pace in five years in April, although the timing of Easter flattered the figures and the outlook was gloomy.

Also this week Britain's two largest electricals retailers, Kesa Electricals and Dixons Retail, both issued downbeat trading updates.

"The latest John Lewis weekly data reinforce our belief that the apparent spike up in retail sales in April should not be taken as a sign that the consumer is coming strongly back to life," said Global Insight chief economist Howard Archer.

Week to May 7 sales at John Lewis' upmarket grocery chain Waitrose rose 10.8 percent to 103.2 million pounds, boosted by the early May bank holiday and continued good weather.

(Reporting by James Davey, Editing by Mark Potter)