An award-winning company told today how staff have had to remove human excrement and toilet paper from their front gate.

Alastair MacMillan, managing director of White House Products, said he could not say for certain that travellers were to blame, but believed it was a ‘coincidence’ the waste was found shortly after they arrived.

He said: “I had to go out with a shovel to clear it up. It was revolting.

“We had the same sort of problem around the place the last time they were here.” The travellers have set up camp on land owned by regeneration body Riverside Inverclyde next to new business park units. Three caravans, a car and a pick-up van full of garden waste arrived on Sunday.

Mr MacMillan said some of his workers who arrive by train have refused to walk past the caravans because they feel intimidated.

He said: “They take a detour rather than pass the caravans.

“If the travellers want to live a nomadic life then they should respect the areas they visit.

“Instead of that they adopt a take, take, take attitude.

“What annoys people is that we know we would not get away with behaving the way they do. They seem to be treated with kid gloves.” One of Mr MacMillan’s employees said: “The travellers even use a pedestrian tunnel under the railway line near here as a toilet.” Their return was condemned by Inverclyde Council’s planning committee chairman and Port Glasgow councillor David Wilson.

He said: “This is not good news. The track record of these people is very bad in terms of the mess they leave behind.

“These caravans do not help Riverside Inverclyde in their attempts to let the brand new units at Kelburn Business Park.” Mr Wilson has previously called on Inverclyde people not to allow travellers to do any gardening or other jobs for them.

He pointed out that they might not return if they didn’t get work.

Riverside Inverclyde say they are aware the travellers have returned to their land.

A spokesman said: “We are dealing with it.” White House Products won the Queen’s Award for Enterprise in International Trade in 2012.

The firm manufactures and distributes £5 million-worth of hydraulic pump and motor parts each year for everything from agricultural tractors to buses and coaches.