OUTSPOKEN federal Liberal MP Alby Schultz has lashed out at business leaders who have told the party it needs to clear out the "deadwood" or risk losing their financial support.

"Faceless, chicken-hearted senior business leaders might think they run the Liberal Party, but the reality is the rank-and-file branch membership will select the candidates for Liberal seats, not business people, nor indeed Liberal leaders or media people," Mr Schultz said yesterday.

The Australian reported yesterday that a document circulating inside the party said business leaders would be unlikely to support the Coalition unless they dumped a group of MPs.

Along with Mr Schultz, the list included Philip Ruddock, Bill Heffernan, Joanna Gash, Bronwyn Bishop, Judi Moylan, Wilson Tuckey, Margaret May, John Forrest, Bruce Scott, Andrew Laming, Michael Johnson, Kevin Andrews and Alex Somlyay.

The document, written by a Sydney business figure who has not been publicly identified, labels Nationals leadership aspirant Barnaby Joyce "divisive".

Senator Joyce challenged the author of the letter to come forward, likening him to "the school child who writes on the back of a public toilet door".

"If you are such a big wheel and so forthright, why can't you give us all your name?" Senator Joyce wrote in a letter to The Australian.

He wrote that people often linked electoral contributions with prescriptions for political success, but that their promised donations inevitably failed to appear.

Ms Bishop said the key to business support was not about deadwood but about standing up for Liberal principles on issues such as asylum seekers and carbon trading. In a veiled swipe at Malcolm Turnbull, Ms Bishop said business would also donate "when they believe your leader can take you to government".

Mr Ruddock said the appearance of the list made no difference to his intention to recontest his safe northern Sydney seat of Berowra next year.

Mr Turnbull rejected the call to purge the Coalition. "Nobody sent that list to me," the Opposition Leader told ABC radio. "Our experience is producing not only an informed and constructive critique of Labor, but (also) the alternative policies that will provide the platform for a recovery."