Lever Brothers is to combat rival Procter & Gamble’s Ariel Tablets by launching “new generation” Persil Tablets, which it claims wash cleaner and protect coloured clothes from fading.

The new Persil Performance Tablets will have two layers, blue and white, rather than consist of a solid white tablet. Lever claims having two layers enhances the product’s cleaning performance.

The new look mirrors P&G’s Ariel Tablets, which have two layers in white and green.

The relaunch will be backed by a £6m advertising spend, through J Walter Thompson, over three months.

The move comes just over a year after Lever first introduced Persil Tablets, in what has been hailed as one of the most successful product launches in the laundry sector.

It has helped Persil regain market leadership in laundry detergents, giving it a 26 per cent value share of the UK market – just ahead of Ariel.

P&G was forced to change one of its television ads, which claimed Ariel Tablets were better than other leading brands.

Lever complained to the Broadcast Advertising Clearance Centre, using the company’s own research to demonstrate that such a claim was unjustified.