Electoral Commission chief executive Peter Wardle has ruled out e-voting in Britain and called for radical changes to electoral law and practice before e-counting is used again.

He was commenting during a Parliamentary inquiry into what went wrong during the Scottish Parliamentary elections in May when 149,000 votes went "missing", which co-incidentally resulted in a Scottish National Party administration replacing Labour in Edinburgh.

"We think e-voting is not a mature technology yet and does not command sufficient confidence to be deployed," said Wardle, whose comments follow an independent report which also rules out e-voting in the short term.

Electronic vote counting has some notable successes around the world but still "raises a range of very important challenges", according to Wardle.

Before e-counting is used against in Scotland a list of criteria must be met, including "a more strategic approach, better coordination, better checking on suppliers and, crucially, looking at the legislation for e-counting".

MPs on the committee were particularly concerned that on May 3 machines rejected ballot papers without referring them always for human judgment.