The agency was called in by the council in July 2009 to help secure funding for the town's regeneration. The contract, worth £130,000, was due to run until January 2011, but council chiefs have responded to pressure from Conservative ministers by ending it early.
The news emerged after a series of attacks by Communities Secretary Eric Pickles on public bodies' use of lobbying consultancies.
Last month, Pickles specifically criticised 'local authorities thinking they need to hire lobbyists in order to be able to communicate with government'.
A spokeswoman for Swindon Council told PRWeek: 'With the change in government, we no longer need the assistance of the consultancy. As a result, we have terminated the contract with Connect Communications early. The firm is currently serving its notice period. This council, like many other public bodies, is facing unprecedented financial pressures and the early termination will contribute to the savings that we have to make.'
An aide to Pickles welcomed Swindon's decision, saying he was 'glad that some councils have woken up and got the message'.
However, Connect director Sarah King insisted the decision to terminate the contract was communicated to the agency before Pickles' latest outburst.
Other councils listed in the latest APPC records as using lobbying firms insisted that this was no longer the case.
Devon County Council, listed as using Weber Shandwick and Bellenden Public Affairs, said it 'no longer uses public affairs consultants or lobbyists'. Hertfordshire County Council said contracts with Weber Shandwick and PPS had expired in April 2010 and that no new contracts were in place.
However, Sunderland City Council defended its ongoing contract with Weber Shandwick. Council comms director Deborah Lewin said: 'We use Weber Shandwick to support our public affairs work - the role is primarily about helping us build our profile and influence at a national level.'
Lewin also argued that, being based in the North East, the council faced logistical problems maintaining regular engagement with Westminster and Whitehall: 'By using Weber Shandwick, we can address this issue in a way that is manageable, effective and efficient.'