The Government's food watchdog will consider recommending that folic acid be added to bread to reduce the number of babies born with spina bifida, it emerged today.

A spokeswoman for the Food Standards Agency said it was being put forward as the "preferred option" to its board when it meets tomorrow.

It is being asked to launch a consultation on the issue at the end of which it will issue advice to ministers.

A briefing paper for the meeting says initial discussions with the bread and milling industry has taken place.

It indicates that their preferred option would be to add folic acid to all flour except wholemeal at the milling stage.

The document also estimates the cost to industry at around £700,000 a year while warning there would be "general ethical population concerns about prospect of 'compulsory' or 'mass medication' issues".

Advice to women expecting to become pregnant to take folic acid to cut the chance of their babies being born with neural tube defects is not being followed up by large numbers of women - especially as half of all UK pregnancies are unplanned.

The defect affects between 700 and 900 pregnancies in the UK every year.

Countries that have started compulsorily adding folic acid to flour have seen a 30-50% drop in numbers.

One concern about introducing that here would be that it could delay the diagnosis and treatment of vitamin B12 deficiency in older people.

It was largely due to this concern that the FSA board in 2002 rejected a report from 2000 which recommended adding folic acid to flour.