The WA government's massive damages claim against builder John Holland for the unfinished Perth Children's Hospital has increased after it was revealed a private contractor is getting $500,000 a month in taxpayer money for an unused car park.

WA Health Minister John Day says the government will demand John Holland pay back an amount expected to reach at least $2.5 million. That is on top of the tens of millions of dollars in liquidated damages the government will already claim due to faulty fixtures and delays of more…