Extra money put in ministers' pay pool

The Turnbull government has quietly set aside an extra $500,000 for ministers' salaries.

Special Minister of State Scott Ryan has approved an increase in the annual amount that can be appropriated for ministers' salaries from $5 million to $5.5 million.

It is understood the government considers the extra money a routine contingency and it's not expected the total amount of the increase will be needed.

The prime minister earns just over $500,000 a year while cabinet ministers earn about $336,000.