It remains unclear whether the Treasury's first chief scientific adviser, James Richardson, is the "poacher or the gamekeeper for the scientific community", according to Andrew Miller, chair of the Commons Science and Technology Committee.
Mr Miller made the remark after Dr Richardson appeared before the committee last week. Before his surprise appointment in June, the Treasury was the only Whitehall department without a science chief.
Dr Richardson, who is also the Treasury's chief microeconomist, said he would not set aside a specific amount of time for his science role, nor would he be "the person in the Treasury who tries to solve every problem involving evidence".
Rather, he would "enforce and enable wider links between the Treasury's well-established social science machinery and the broader natural science community" and promote a "better standard of scientific method, evidence and analysis so that whoever is the lead official on any issue is better equipped".
Dr Richardson will also influence how the Treasury's research budget, totalling £500,000 over the four-year Comprehensive Spending Review period, is spent.
However, he insisted that he would not lobby for an increased science budget: "The Treasury holds the ring: it shouldn't also be a player in that ring."
Sir John Beddington, the government's chief scientific adviser, told the committee that although Dr Richardson was not a natural scientist, he would learn from the network of departmental science advisers who provide a "real cross-section of key areas".
He said he hoped the vacant chief scientific adviser posts at the Department for Transport and the Department for Business, Innovation and Skills would be filled by Christmas.
The government is examining whether one of the appointees could also cover the Department for Culture, Media and Sport, which is "significantly downsizing".
Meanwhile, an analysis by the Campaign for Science and Engineering has warned of an "alarming decline" in UK science funding, despite political pledges to protect investment.
A report published by the lobby group on 14 September says that by 2014-15 the research base will be £1.6 billion a year worse off in cash terms as a result of decisions taken since the CSR last autumn.
It claims that the government has made the cuts while still maintaining that science funding is ring-fenced by redefining what is meant by the term "science budget" - for example, removing capital funding for research from the equation.
Lord Rees, former president of the Royal Society, said CaSE's findings were "disquieting".