Two-foot trenches have been dug, water pipes laid and septic tanks installed on the greenfield site near St Florence.

Simon Hart MP is keeping a close eye on what is feared to be an illegal gypsy encampment springing up near Tenby.

Mr Hart has been to the site twice after worried local residents told him what was happening.

"It looks as if a major scheme is imminent – a lot of preparatory work has taken place on this field, perhaps with a view to installing caravans or chalets but it has no planning permission and any development would be illegal," said Mr Hart.

"When I visited on Saturday there was a septic tank awaiting installation and workmen digging trenches and putting in multiple water supplies."

Mr Hart has spoken to Pembrokeshire County Council's Planning Enforcement Officer and Director of Planning about the matter.

"They are fully aware of what is going on and have already started the legal process needed to put a stop to any development," he added.

"Unfortunately there is a history of illegal camps springing up over long bank holiday weekends when the planning authorities are on leave and I have asked the council to be preemptive rather than reactive."