The Leader of the Commons is the first serving member of the Cabinet to endorse publicly such a radical change in Britain’s democracy.

In a speech to the left-wing Institute for Public Policy Research think-tank in London, Mr Hoon will say that the measure is necessary to counter the low level of voter turnout.

He is expected to say that the 61 per cent turnout in May’s general election left him “more concerned about our democracy than ever before”, adding: “We are seeing not just twentysomething’s but people in their thirties and forties who have never voted and who actually seem proud to say so.”

He will claim that the spread of deliberate non-voting threatens “the long term legitimacy of our political system”.

The former Defence Secretary said it was embarrassing that turnout was higher in Afghanistan, where 77 per cent of people voted last year, and not much higher than the 58 per cent of people who took part in Iraqi elections this year. In both countries, he says: “Men and women queued in their thousands — risking their lives in defiance of terrorists — to cast a vote for their future.”

Since becoming Leader of the Commons, Mr Hoon has spoken out against the cynicism with which many people regard politicians from all parties, as well as the need to treat those holding public office with more respect.

In the speech today he will state that it is not apathy nor sloth or contentment that is undermining participation in British elections but “alienation — the feeling among many people that their vote will not change anything”. He will say that this is particularly true among the poor and more disadvantaged groups.

But Mr Hoon is also expected to say that the way in which political parties are becoming increasingly sophisticated in pursuing those who do vote means that those people staying at home could become further marginalised from the process.

“This will alter our democratic debate, risking encouraging a greater focus on issues of concern to the chattering classes and neglecting issues of wider and more general concern. It is profoundly dangerous for our political life.”

He will suggest that voting itself need not be compulsory, instead saying that all that would be required would be attendance at a polling station or registration for a postal ballot. “It is vital that there should be an option available to abstain or spoil your ballot paper,” he will say.

Mr Hoon believes that enforcing such a measure could include imposing a small fine.