The Western Australian construction union has hit out at a ban on building workers eating ham sandwiches and meat pies at the building site of a $70 million mega-mansion.

Tradesmen and laborers working on the property have been told by Indian-born billionaire Pankaj Oswal and his socialite wife Radhika, that any food containing meat must not be consumed on the site.

Once complete, the $70 million s Taj-on-Swan mansion will be the biggest home in the country, on the most expensive block of land. It is located in the exclusive suburb of Peppermint Grove in Perth.

Construction, Forestry, Mining and Energy Union Western Australian assistant secretary Joe McDonald said the ban was “absolutely wrong”.

“She still wants them to build her $70 million mansion, but she’s telling them what they’re going to eat . . . it’s wrong,” he said.

“I respect everybody’s right to practice their religion, but I totally disagree with anyone forcing it on others.

“That has caused more wars and destruction throughout the world than anything else I know of.

“If people are working on the job and they want to have a ham sandwich or a bacon and egg sandwich, they should have one.”

Workers on the site yesterday said there was one small shed at the bottom of the site which they were allowed to eat meat in.

A source close to the Oswals, who did not want to be named, said some workers had continued to eat meat on the site “just to spite them”.

Mr Oswal, who is in New York this week helping Mrs Oswal prepare for the launch of her vegetarian fast-food chain, Otarian, defended the meat ban, saying “This is our home”.

Mrs Oswal has previously accused the meat industry of “raping the earth”.

“Meat eating is creating bad karma and you are also creating a vicious cycle,” she said.

“It’s destroying us environmentally, economically and socially. I’m putting my money where my mouth is. I’ve always been a vegetarian so I have always felt strongly about it.

“First, because of religious reasons, but then later because I realized the greater good associated with it.”

The house, expected to be finished at the end of 2011, will have a gymnasium the size of a regular Perth house, a beauty salon, an observatory, parking for 17 cars and a swimming pool 10 times bigger than the average back yard.