Thousands of people have signed a petition against any plans by Nato to hold military exercises in Ukraine.
Stop The War Coalition, CND and a number of politicians and celebrities have submitted the petition to the Government's e-petition site in a bid to have a debate in Parliament and prevent any UK troops being deployed.
A spokesman for the Stop The War Coalition said holding manoeuvres in Ukraine was a "dangerous move" which would "inevitably escalate" an already tense situation.
The petition reads: "We note with great concern that UK and US troops are scheduled to participate in joint military exercises in Ukraine in July as part of Nato's Rapid Trident manoeuvres.
"Ukraine is not a member of Nato. Its participation in military exercises by a nuclear-armed alliance with a first-strike policy can only further destabilise the country.
"We call on the British Government to urge the US and other Nato governments to cancel the Rapid Trident exercise, and to give a plain and public undertaking that Britain will not participate."