The lesson from Eastleigh is simple: the Conservative leadership has lost control of the party

The Eastleigh by-election campaign enters its final week today, billed from the beginning as a battle of intense significance between the two Coalition parties, and as a test of Ed Miliband’s claim to lead a “one-nation” party.

Within moments of the previous MP, Chris Huhne, announcing his resignation, the contest was seen as a very big challenge for the party leaders. Not surprisingly, all three have visited the constituency.

Given the supposedly high stakes, there is a striking oddity about the by-election. From Day One of this make-or-break contest, the Conservative candidate, Maria Hutchings, has spoken with a defiantly independent voice. As David Cameron sought broader appeal for his party by supporting gay marriage, Hutchings declared that she was opposed.

On the thorny issue of Europe, she delivered a different message from the leadership, making clear that if there was a referendum today, she would vote for the UK’s withdrawal. Her comments on her choice of schools for her children have led to awkward clarifications from those running her campaign.

As far as possible, her meetings with journalists, especially those from the national media, are kept to a minimum. Some Conservative MPs who have visited the constituency are downbeat, expressing concern that they have got the wrong candidate. She is not what any national leadership would regard as an ideal candidate for a high profile by-election.

It might be that Hutchings’ outspokenness and blunt authenticity will have a populist appeal, but, whatever the outcome, some voters will note the discordance between the messages from the national leadership and its candidate. Voters can tell when all is not quite right. The awkward relationship between the national and the local contrasts with the relatively smooth campaign fought by a Liberal Democrat machine, one that is showing that in certain parts of the country it remains reasonably well-oiled in spite of the impact on the party that Coalition has had.

On one level, the Conservative leadership has little excuse for the selection of a candidate who expresses views at odds with its own. This is not a by-election that has arisen suddenly and unexpectedly. For more than a year, it was at least a possibility that Huhne would be forced to resign. There was plenty of time for the Conservatives to find the right candidate – someone who could remain unambiguously loyal while at the same time pitching a message that would have local appeal.

There is a clear and – for the national Tory leadership – disturbing reason for what has happened. The leadership is no longer in control of the party. At a local level, the Conservatives are discovering assertiveness more familiar to Labour in the 1970s and 1980s. The local muscularity is not as extreme as Labour’s was during those two unruly decades, but there are parallels in ideological restiveness, wariness of leaders and in the inevitable tensions that arise in by-elections when the performance of a local party can have an important impact on the fate of the national leadership.

An illuminating comparison can be made between Labour’s 1997 intake of MPs and the Conservatives elected for the first time in 2010. The response of most Labour MPs in 1997 was to be genuinely loyal to the leadership and for that enthusiasm to be combined with intense ambition to become ministers. There was much talk about “control freakery” at the top, but most of them were happy to be controlled. Parts of the 2010 Tory intake are markedly more independent – almost as a matter of principle.

To some extent, the model is Douglas Carswell, who was elected five years earlier. In an interview with The Independent last summer, Carswell outlined how quickly he had become disillusioned with parliament:“““It seemed that our primary function as MPs was to provide the cheerleader chorus for the front bench. I thought Parliament and the House of Commons were one giant conspiracy against the electorate. I felt this incredible sense of liberation when I realised that I wasn’t going to play the game.”

For honourable reasons, quite a lot of the new Conservative intake will not play the game. The MP Andrew Percy dared very early in his parliamentary career to vote against the increase in student fees. In a BBC interview last year, he told me emphatically that his loyalty was to his local party and constituents rather than the national leadership. In the same discussion, for different reasons, the MP Caroline Dinenage agreed that she had a similar sense of loyalty to her local party.

Before the last general election, the local Tories in Gosport held a US -style open primary pre-election, inviting all constituents, of whatever political affiliation, to complete a postal ballot to pick their favourite candidate. Dinenage won and says she feels an intense sense of duty to the constituency as a result. Long-serving MPs tell me they note that Westminster is emptier than it used be because more of the elected representatives regard their paramount role as serving in their constituency rather than speaking for the national leadership in parliament and beyond.

The consequences of the new local assertiveness are especially vivid when a by-election is held. If a local candidate speaks her mind, the differences with the national leadership are bound to be a theme.

In the 1980s this happened so often to Labour that its leaders went almost crazy, most particularly when the party’s candidate for a by-election in Greenwich was far from what Neil Kinnock would have regarded as ideal by-election material. The by-election took place not long before the 19897 general election and Labour did not win. Had it done so, the result would have given Kinnock much-needed momentum. But he could not control the choice of candidates at that stage of his leadership.

The stakes are nowhere near so high in Eastleigh. Each leader has got a legitimate excuse if his party loses. Cameron can argue that governing parties rarely gain seats in mid-term. If Clegg loses, he will point to the circumstances of Huhne’s resignation. Miliband can argue that his party started third in a two-party battle and was never going to get much of a look-in. Leaders have their protective shields. The contest will not hasten their demise.

But whatever the result, the by-election marks another important stage in the pre-eminence of local Conservatives deciding what to do and say, and a nervy national leadership having no choice but to let them.