NCA Chief Executive officer, Gary Rake at the temporary car park next to the National Library known as the Patrick White Lawns. Work will begin Friday week to turn the car park back into a grassed area.

National Capital Authority's Gary Rake in the car park next to the National Library. Photo: Melissa Adams

The second-in-charge of Questacon has left safe public-servant speak behind to urge authorities to ''show some leadership'' and fix the ''appalling'' parking situation in the Parliamentary Triangle.

And the National Capital Authority has promised to look at putting more short-term car spaces near the cultural institutions to stop workers in the Triangle hogging the spaces.

Questacon's general manager operations Lorraine Neish said an already unacceptable situation was about to get worse, with the NCA planning to close a temporary car park in front of the National Library in less than a month to restore the Patrick White Lawns, which lead down to Lake Burley Griffin.

The prospect of paid parking in the Triangle has been a political football for years, with unions representing public servants opposing it and committees issuing discussion papers about it but very little changing in the meantime.

While not calling specifically for paid parking, Mrs Neish said the closure of the temporary car park next to Questacon would ''have a significant and detrimental effect on our visitors who will be completely displaced by workers who will move into the available [spaces]''.

''The current situation will become immediately more frustrating for visitors, both local families and also those who have travelled long distances to visit Questacon.

''To see them drive around in circles and see them ultimately give up and leave the area is appalling. This is not the experience that they came for. It is essential that the visitors to the nation's capital have a wonderful experience and that their tourism and educational needs are high on our priority list.

''Workers who currently occupy the Patrick White Lawns and the lakeside car park have options in the broader area. It is time that leadership is shown to address this … issue.''

The National Library's director-general Anne-Marie Schwirtlich said she also wanted to ensure that the many visitors to the library had access to convenient parking.

''Given the growing number of visitors we receive daily - ranging from young families to seniors - the library is concerned that there is both sufficient parking in the library's proximity and that there is the correct mix of short-term and long-term parking,'' she said.

''Our researchers and volunteers, for example, would need all-day parking while other visitors who come for lunch, events or to see one of our exhibitions, are generally looking for shorter term parking.''

The little-known Patrick White Lawns, honouring the late writer, were created in 2004 but became a temporary gravel car park in 2007.

NCA chief executive Gary Rake said the car park was never meant to stay but had done so in part because the authority did not have the money to restore the lawns. He said it now had $150,000 to restore the lawns, with the gates to the temporary car park to close on August 3 and the lawns to be finished by the end of the year. The area will still be used for one-off events such as car shows, but Mr Rake said that was different to the area being used by ''a couple of hundred cars every day''.

Mr Rake said he had spoken to the heads of both Questacon and the library and understood both had concerns about the mix of parking in the area. The authority was looking at trying to get more short-term spots closer to the institutions. He said he had already received other objections from people concerned about the loss of parking.

The Patrick White Lawns also sit within the Parliament House Vista, a place included on the Commonwealth Heritage List. The Parliament House Vista Heritage Management Plan lists the restoration of Patrick White Lawns as a high priority ''to improve the condition and integrity of the area''.