A Liberal candidate's bid to gatecrash one of Bill Shorten's campaign events has backfired spectacularly with a car-crash media interview.

Chris Jermyn found himself unable to articulate the Coalition's health policies before declaring his hatred for journalists and beating a hasty retreat.

The Liberal candidate for the Victorian seat of McEwen showed up at Mr Shorten's event at the Sunbury Community Health Centre on Saturday. Mr Shorten shook his hand on his way in, joking that at least he was getting to see one leader this election.

But in what's being billed as a "Jaymes Diaz moment" - referring to a Liberal candidate who was famously unable to outline his party's position on border protection at the 2013 election - Mr Jermyn was at a loss to explain Coalition policy in an interview.