Travellers' caravans have been spotted on green land in Yiewsley , near the Tesco superstore.
It has been reported there are around 50 caravans on land at Philpott's Farm just off the High Street.
The travellers are believed to have set up camp on the site at around 9pm on Wednesday night (July 13) after they were said to have 'broken in'.
One witness said: “Travellers have broken into Philpott's Farm, Yiewsley, opposite Tesco. Estimated 50 caravans and rising.”
Pictures have emerged showing the caravans in the field as well as images of rubbish dumped nearby.
Another witness reported a police presence on the scene.
Hillingdon Council member for West Drayton , Jan Sweeting, said she had not seen the travellers on the site, but that she was confident the council would handle the situation.
Cllr Sweeting said: “The council is very good on issues relating to people occupying land which is not theirs.
“It's a very much cherished piece of land in quite an urban environment.”
The Yiewsley traveller camp follows another in Ealing, where caravans returned to Norwood Green this week only days after a previous group left the site .
