As revealed on prweek.com, Collins starts the new role next week. He replaces David Sowells, who is to take up a new role in Washington working for Bell Pottinger USA.
The hire will be seen as a coup for Bell Pottinger at a time when heavyweight Tories are in short supply.
Before entering the Commons in the Labour landslide of 1997, Collins served as press secretary to prime minister John Major and as a member of the Downing Street policy unit.
Following his election as an MP, Collins went on to become shadow transport secretary under Iain Duncan Smith's leadership of the Conservative Party, then shadow education secretary under Michael Howard.
At the 2005 general election, Collins lost his seat to Liberal Democrat Tim Farron and has been running the family business since then.
Collins will work closely with Peter Bingle, chair of the agency's public affairs practice. Bingle commented: 'It is great for us and our clients that Tim has agreed to join BPPA at this fascinating time. He is a serious person with a long and distinguished history in the Conservative Party.'
Collins said in a statement: 'It has never been more important that those making public policy, and those affected by it, should understand and trust each other and exchange ideas and information to help make the country run better.'
The hire is the latest indication of the determination that exists among public affairs consultancies to snare a Conservative. It comes weeks after Portland PR hired Conservative Party heavyweight Michael Portillo to be a part-time adviser.
Fleishman-Hillard also recently moved to strengthen its Tory firepower by hiring a trio of Conservative lobbyists including Andrew Cumpsty, leader of the Conservative Group on Reading Council. However, with many Tory aides choosing to stay put, some agencies have struggled in their quest to hire a Tory.
Seperately, Bell Pottinger Public Affairs has been retained by international coach operator Eurolines to advise on its engagement with EU institutions.