Campaigners opposed to the expansion of Heathrow have claimed to have bought a piece of land needed by BAA for a third runway.

Greenpeace has divided up the football pitch-sized plot into tinier plots with separate owners, hoping to force a lengthy legal battle when BAA has to buy the land through compulsory purchase.

A decision on the expansion of Heathrow now looks likely to be delayed as prime minister Gordon Brown prepares to meet with backbench MPs opposed to the plan for a third runway and sixth terminal.

Last night demonstrators from Climate Rush held a peaceful protest in Terminal 1 when they staged an Edwardian-style picnic dressed in costumes from the era to revive memories of the suffragette movement. There was no disruption to flights.

Reports today suggest that protesters plan to use the plot of land near the village of Sipson, which was bought for them by a secret donor, will become the site of a Newbury bypass-style protest with a network of tunnels if work starts on the runway.

Among owners of the smaller plots are comedian Alistair McGowan, actress Emma Thompson and Conservative environment adviser Zac Goldsmith.

The government is still expected to give the go-ahead to the expansion of the airport, a move backed by trade unions and business leaders.

However, it is expected there will be some conditions attached on air and noise pollution if the number of flights is increased, and the airport could be set stringent punctuality targets.

• Business leaders and unions back Heathrow expansion (12 Jan 2009)

• Heathrow to overhaul runway system (5 Jan 2009)