The review comes after a brand revamp in March and the introduction of the strapline, "Warburtons. We care because our name's on it", to emphasise the product quality. Warburtons is in the early stages of reviewing its current roster.
Agencies working for Warburtons include Arc Integrated Marketing, Brahm, WARL and the Brass Agency.
Advertising, which is currently handled by Rainey Kelly Campbell Roalfe/Y&R, and media planning and buying, which is through Mindshare, are not affected by the below-the-line review.
RKCR/Y&R won the £10m ad account last year when Warburtons split with Bartle Bogle Hegarty after 12 years. The agency won the business following a competitive pitch handled by Warburtons' marketing director, Richard Hayes.
The most recent Warburtons ad, launched in April, parodied a Hollywood epic to promote its credentials as the caring baker.
The ad featured a burning loaf of bread being baked in the factory. The employees at the factory all looked on with sadness as the loaf was taken away and given a proper burial, reacting as if a person had died.
Recently, the brand has looked to raise awareness of its new snack range, ChippidyDooDaa pitta chips and SnackaDoodle, which it introduced in March.