The Minister for the Environment, Martin Cullen, has launched an advertising campaign to explain the new electronic voting system to the public.

Electronic voting is to be used throughout the country for the first time in next June's local and European elections.

Speaking on RTÉ Radio this afternoon, Mr Cullen rejected claims by the Opposition that the system has not been proved to be fully secure. However, he agreed that a vote could not be spoiled in total secrecy.

Electronic voting was used successfully in three constituencies in the last general election, and in seven in the second Nice Referendum.

Critics of the system have sought a way of ensuring that the vote can be checked, with a paper version of the ballot, checked by the voter, which can be used if there is a recount.

However, experts say there is no machine offering such a safeguard, and that on a technical basis it would be very difficult to achieve.