The controversial My Health Record system has been dealt another blow, with a Federal Liberal MP abandoning his government’s own scheme.

Labor is urging the government to extend the opt-out period beyond three months.

Melbourne-based Liberal MP Tim Wilson has revealed he withdrew from the scheme within days of the opt-out period opening last week.

“People should be able to be free to choose to opt in to a system,” Mr Wilson told Sky News.

“My instinctive position should always be, as a liberal, that systems should be opt in.”

Despite attacking the system’s design, Mr Wilson said it could deliver benefits “in terms of efficiency and access to your medical records”.

Privacy advocates have urged Australians to avoid the system, amid warnings the database is a tempting target for hackers.

About 20,000 people opted out last Monday when the withdrawal period began.

Health Minister Greg Hunt has previously said “any individual” could opt out if they had concerns.

“They don’t have to be part of the system. Nobody has to be part of it,” Mr Hunt said. “But everyone should have the right to their own records.”

Shadow Health Minister Catherine King has called for an extension of the opt-out window.

“The government has failed to effectively communicate with the public about what the My Health Record is and the potential benefits it could bring,” Ms King said.

“It has also failed to explain to people how their rights will be respected and their privacy protected.”

The Opposition has called for a new advertising campaign to inform the public about the scheme.

A Turnbull Government spokesman said the My Health Record project had a communications budget of $114 million.

The government agency responsible for the My Health Record said the opt-out system had been broadly supported by clinical and consumer peak bodies as well as the Federal Opposition.

-ABC