Plans to restrict postal voting and introduce ballot box identity checks are being floated by an election watchdog to help crack down on polling fraud.

The British voting system is vulnerable to abuse even when all current measures are being taken to prevent and detect it, according to the Electoral Commission.

It found a consistent underlying level of concern among voters about fraud but reports of wrong-doing were concentrated in a small number of English local authority areas.

Jenny Watson, chairwoman of the commission, said: "Although the law has been changed over the years... our research shows voters are still concerned about electoral fraud."

Overall, there was no evidence of widespread electoral fraud in the UK, but there were strongly held views that fraud was more likely to be committed by, or in support of, candidates in areas with South Asian communities. The commission stressed there was "an absence of robust evidence in this area".