Julie Bishop is the latest Turnbull government minister facing scrutiny over taxpayer-funded travel claims, amid growing calls for an overhaul of politicians' travel expenses.

The Foreign Affairs Minister charged taxpayers $2716 to attend the Portsea Polo event on Victoria's Mornington Peninsula in January last year as a guest of beer maker Peroni and car company Jeep.

On Wednesday, Ms Bishop's office defended her expense claims to attend the exclusive event.

"The Minister was invited and attended in her official capacity as Minister for Foreign Affairs and Deputy Leader of the Liberal Party."