A gipsy encampment has sprung up just 200 yards from the Warwickshire home of government minister Tessa Jowell.
Dozens of travellers piled on to the site over the bank holiday weekend, setting up a water supply and laying electricity cables.
A septic tank has been installed and concrete pathways laid on the site, near the town of Shipston-on-Stour. Fencing has also been erected and hedges have been pulled down.
Residents reported the caravans moved on to the two-and-a-half acre site on Friday, leading to accusations that the gipsies were taking advantage of the public holiday when nobody at Warwickshire County Council was working.
The field, which has space for at least 30 caravans, is just 200 yards from the country home of Olympics Minister Tessa Jowell, 60, and her estranged husband David Mills. It was reported the gipsies had bought the site from a local businessman.
Conservative councillor Chris Saint represents the area on Warwickshire County Council. He said: "Up until last Thursday it was simply a piece of pasture land. On Friday morning I got a call from one of the parish councillors to say that there was some frenzied activity taking place on the field.
"We view it with alarm because I have no information about a planning application even being lodged, let alone granted, and I would be the first to know.
"I understand that water and electricity have been brought on and I also understand they have put in a sceptic tank and put down roads and fencing."
Asked whether he thought the gypsies had targeted the bank holiday weekend as no-one would be working at the council's offices, Mr Saint added: "We don't know that for certain but the speculation is that they have done this because there is a four day window when officialdom is unlikely to get to them.
"Myself and colleagues have reported it to the local government offices over the weekend but the key person will not be back at their desk until tomorrow morning."