Prime Minister Malcolm Turnbull says the Liberal Party was too broke to pay its federal director for several months in 2015 as he defended his record-breaking $1.75 million donation to boost campaign coffers.

Appearing to confirm speculation that donations to the party had all but dried up under the leadership of former prime minister Tony Abbott and infighting among party office-holders, Mr Turnbull told Channel 9 that federal director Tony Nutt had been asked not to take a salary for a number of months after taking on the job in October 2015.

On Monday, Mr Abbott hit back.

"Due to the good work of the director and office-bearers, the party was always able to meet its costs in my time as leader," Mr Abbott said in a statement to Fairfax Media.