Banks Sadler has confirmed that up to nine of its 89 London-based staff may be made redundant.
The agency's chief executive, Leigh Jagger, said posts in its York, Warsaw, Paris and Dusseldorf offices would be unaffected.
The redundancies come in the wake of the agency - which employs 89 employees in London, 39 in York, three in Germany, three in Poland and four in Paris - taking "some big cancellations two weeks ago".
"This has been a very difficult decision to make and it is distressing to lose anyone from our dedicated and hardworking team," said Jagger.
"Everyone has worked hard to avoid this situation, but the current economic climate is taking its toll on all in the industry. Despite winning several new accounts in the past few months the business from these new clients is not yet enough to offset cutbacks in other areas."
The agency was awarded Gold at the Eventia International Awards on Friday for Best Incentive Travel Programme - Short Haul for its work with pharmaceutical firm Lilly.