The centre needs the money to achieve its full vision for its own dialysis capability and home palliative care support.

Ms Kealy said Victorian Health Minister Jill Hennessy had promised to help fund any shortfall during a visit to Horsham in May.

“Jill Hennessy looked local cancer patients in the eye while receiving treatment and promised she would provide additional funding to build the Wimmera Cancer Centre if required,” Ms Kealy said.

“The Minister promised local people on May 13 that the government was prepared to allocate extra funding if needed and was quoted: ‘If you don’t get there, we will, we’re going to build this. This project is not going to stop if the community fundraising falls short.’

“It is extremely disappointing that it appears the Minister is reneging on her promise, meaning the Wimmera Cancer Centre which includes cancer treatment, dialysis and palliative care may not be built.”

Ms Kealy said copies of the petition would be available from her Horsham electorate office and will be posted on her website.

“The petition will send a clear message to the Minister that she must provide the additional $1.5 million required to build the Wimmera Cancer Centre,” she said. 

“We will not accept the Minister breaking her promise to cancer, dialysis and palliative care patients.”

A spokesperson for Ms Hennessy has previously said that the minister would work with Wimmera Health Care Group to examine and overcome the ‘cost blow-out’.

“Last year the Andrews Labor Government provided the $1 million needed to get this project off the ground,” the spokesman said. 

“We will continue to work closely with the health service to try and get to the bottom of this cost blow-out, and determine what action needs to be taken next.” 

The cancer centre project reached its minimum $1 million community fundraising goal in August and will start construction in the next few months with a completion date later in the year.  

Ms Hennessy said during her visit to Horsham and Wimmera Base Hospital last year that the cancer centre was incredibly important.

"If you don't get there, we will," she said at the time.

"We're going to build this. This project is not going to stop if the community fundraising falls short."

In May 2015, then Prime Minister Tony Abbott committed $1 million in federal money for the cancer centre.

The state government has contributed $1 million and Wimmera businesses and the Horsham Rural City Council have donated amounts of up to $75,000.

In October, Wimmera Health Care Group revealed that the centre would be built on the corner of Arnott and Robinson Street in Horsham overlooking Jadwa Park.

Demolition works have started at the site with construction due to start in the middle of this year.