''I made it clear when I took up the role that I was hopeful to have the CEFC fully established and operating by the end of March such that we could document transactions in April, May, June, that would be funded in July.''

In a letter sent to the corporation's board on Monday, the Coalition's finance spokesman Andrew Robb and climate action spokesman Greg Hunt said the opposition did not support the corporation and asked it to desist from entering into contracts or releasing funds now that September 14 had been declared the date of the next federal election.

The letter said if it wins office the Coalition would not allocate funds to or accept agreements struck by the corporation after 1 July because it believed the country would ''effectively be a caretaker period''.

''Any rush of taxpayers' funds via the CEFC so close to an election would be totally inappropriate in our view and would be interpreted as a political exercise aimed at influencing an election outcome,'' the letter says.

While not speaking directly to the Coalition's letter, Mr Yates said the law was clear that until legislation governing the clean energy finance corporation was changed the corporation had an obligation to undertake its business by making investment decisions and loans.