The decision will end Proximity London's six-year relationship with the brand. Its contract expires at the end of the year.
The review follows the appointment of Dominic Traynor as the relationship marketing manager in January. Traynor, who oversaw the pitch, said he decided to split the brief between two agencies because of the scale of the brand.
Tullo Marshall Warren already handles Comfort fabric conditioner and recently strengthened its relationship with Lever Fabergé when it was handed the brief for its Vaporesse ironing liquid.
However, it is the first time Tequila will have held a laundry account.
Persil has relied heavily on direct marketing over the past few years. Recent work from Proximity included a 250,000 direct mail campaign to back the launch of its range of liquid bottles.
Persil's above-the-line advertising account is held by J Walter Thompson and its media planning and buying is handled by Initiative Media. Neither account is expected to be affected by the review.
If you have an opinion on this or any other issue raised on Brand Republic, join the debate in the Forum here.