Prime Minister Gordon Brown visited Oxford University today announce ambitious targets to increase the numbers of pupils studying sciences and maths in state schools.

Mr Brown visited a bio-chemistry facility in South Parks Road, before giving a lecture at the Sheldonian Theatre.

Mr Brown argued that investment in science was key to Britain’s future competitiveness and promised not to let science become “a victim of the recession”.

He announced initiatives to encourage science, maths and IT graduates who lost their jobs to retrain as teachers, as part of a drive to ensure almost all state schools offered physics, chemistry and biology as separate subjects within five years.

Mr Brown insisted scientific advances should continue, despite the economic climate.

He said: “Some say that now is not the time to invest but the bottom line is that the downturn is no time to slow down our investment in science but to build more vigorously for the future.

“And so we will not allow science to become a victim of the recession.”

In the afternoon, Mr Brown visited the new £109m cancer centre at the Churchill Hospital, where there will be an open day on Monday.

The centre, which will provide all cancer sevices under one roof, opens to patients on Monday, March 16.

Mr Brown said: “This hospital is a great example of new investment that will yield a great deal of comfort for patients.”

Vickie Holcroft, director of relocation for Oxford Radcliffe Hospitals, said: “We are delighted that the Prime Minister has chosen to come here. We have had an opportunity to show him how well public money is being spent.”

At the university, Mr Brown was giving the annual Romanes lecture, which was first given by William Gladstone in 1892.