Agencies are expected to be seen in June and the successful candidate will start work in July. The account is currently held by Countrywide PorterNovelli.
The bulk of the work will be to assist newly appointed Transport Action PR manager Penny Andrews to promote £60m of grant schemes. Transport Action was formed in 2000.
Grants are primarily available to help convert cars to alternative fuels such as liquid petroleum gas and to fit emission reduction equipment to diesel-fuelled vehicles.
Earlier this year, EST announced it was to stage pitches for two other external PR support accounts, for corporate and public affairs and local authority liaison.