However, since protective barriers were removed, the attraction is so strong that people are sometimes placing a hand on the painting as they pose with the likes of John Howard or Paul Keating.

Some staff at Parliament House are concerned about the practice of visitors touching the paintings, since the public area was given the look of a modern gallery, with no barriers in front of the art works.

However Carol Mills, the head of the Department of Parliamentary Services who made the decision, says there has been no damage to the art works.

‘‘We did a trial of removing the barriers in one particular area in the public area and we observed that for a few months and didn’t see any discernible change in behaviour,’’ she said.

“We would like no one to touch the paintings, on the other hand we want people to get close.

“So we’ve gone to what I would call a more normal gallery approach.

‘‘People have occasionally said some people are touching paintings but we monitor them and we’ve not seen any damage.’’

The previous barrier was thick rope strung at waist level between brass posts and which would not have prevented anyone determined on vandalism.

Betty Churcher, a former director of the National Gallery, said in a report on Parliament House’s art collection, that the important paintings earmarked for semi-permanent display in open-access public spaces should be ‘‘sturdy enough to withstand accidental and very occasional contact – oils on canvas or acrylic on canvas’’.

‘‘If protective barriers are used they should be unobtrusive and at shin-height, so as not to interfere with the enjoyment of the display. No barrier will protect a work of art from a vandal with malicious intent,’’ she said.

A staff member who works in another part of the building has observed people putting their hands on the painting of a former prime minister as they posed to have their picture taken.

Ms Mills said the rope and post barriers were not art gallery standard or design and struck her as unusual.

‘‘Rather than being truly protective, they were more just a visual obstacle because they were big and loopy, there was nothing to stop you still touching the work,’’ she said.

“What a gallery would normally do would be to have something much more discrete that didn’t take away from the image of the artwork itself.

“Some galleries do that with very thin wire at knee height, some do it with just markers on the ground and a lot of galleries don’t have anything but have staff watching and who speak to you if you come too close.

“Some have alarms for very valuable art works and some have perspex or glass over the paintings.’’

A perspex cover was recently added to William Dargie’s portrait of the Queen, known as the "Wattle Painting’’.

Ms Mills said the painting was more popular and more valuable than the Prime Ministers’ portraits.

“A lot of people do have their photo taken in front of it,’’ she said.

“It’s a very lovely painting and it’s one of the most colourful works in the public area where we have more of the traditional portraits, it stands out because it’s the wattle queen.

‘‘We have a lot of international guests – she’s a recognisable person whereas the prime ministers wouldn’t necessarily be.’’

Ms Mills said the rope barriers were put back for major events if the building is expected to be crowded, such as for budget night or the opening of Parliament.

“Since we did the trial and then brought more of the ropes down, we’ve had no cause to feel that was the wrong thing to do but we do look regularly at which works should be covered,’’ she said.

“It is important for us to reinforce to people that this is the people’s house and that they’re welcome to come through it.

‘‘Members of the public do behave appropriately in museums and galleries and that way we treat them with respect and we hope they treat our works with respect.’’