RED balloons symbolising the 57 Labour MPs who have expressed concern about expansion at Heathrow will be waved to mark the start of a Commons debate.
Although the discussion and subsequent vote on the need to enlarge the airport will not be binding on the Government protesters are still hoping for a result in their favour.
They will gather in Old Palace Yard, opposite the House of Commons, at 8am tomorrow (Wednesday) to encourage the Labour members to side with the opposition MPs during the vote.
The debate has been called by the Conservatives and is likely to start between 1-2pm with a vote taking place between 6-7pm.
If all the opposition parties vote with the Tories it will require just over 30 Labour MPs to rebel for the Government to be defeated. The 57 people represented by the balloons are known to have signed Early Day Motions calling for the Government to think again on expansion.
John Stewart, chairman of HACAN, said: "This vote will not be binding on the Government but a close result one way or they other would be embarrassing. It would show once again just how little support there is for its plans for a third runway at Heathrow.