About once a decade - seldom more - the people of Britain have an opportunity to opt for a fundamental change in political direction and style of governance. Similarly, our political parties have a chance to redefine their objectives and their appeal. Now is such a time.
A matter of months ago, few people could have imagined a Conservative Party venturing towards the centre ground.
The Liberal Democrats had their own opportunity to drive that part of the agenda in the 90s under the leadership of Paddy Ashdown. The party moulded Liberal and social democratic ideas and consolidated a position in the genuine centre.
The electoral success of the New Labour project was due in part to the Blair/Mandelson strategy of adopting wholesale slices of Liberal Democrat thinking. They enlisted the assistance of some Liberal Democrat strategists and former councillors.
The arrival of David Cameron at the helm of the Tory party has precipitated a shift in the direction and political atmosphere within the party.
Politics is suddenly dynamic and interesting again. Importantly, it now offers - arguably for the first time since 1997 - the only potentially achievable opportunity for "regime change" at the next election.
That possibility would gather more credence if the joined-up forces of compassionate conservatism and genuine liberal democracy were to combine to ensure the departure of our current presidential, autocratic and authoritarian government.
Despite its manifest failures, a lack of effective opposition has allowed Blair to survive - and more worryingly, legislate and regulate almost at will.
The nightmare scenario could be a hung parliament with yet another but weaker Labour administration, led by Gordon Brown, propped up by Hughes-led, left-leaning Liberal Democrats.
So if the Liberal Democrat leadership process settles down into a straight race between Campbell and Hughes, many Liberal Democrats will feel caught between a rock and a hard place.
We need change at the next election: Liberal Democrat centre-ground politicians and thinkers need to consider those choices and opportunities - or live with the consequences. For me, the solution is quite obvious. David Cameron represents the positive, constructive and optimistic politics I believe in. That is why I am joining David Cameron's modern, compassionate Conservative Party. The time has clearly come for others to make the same choice.
Adrian Graves, 57, is a strategic public relations consultant and was Liberal Democrat parliamentary candidate for Suffolk West in 1997 and 2005Reuse content