St Leonards is the plushest corner of this plushest of constituencies. North of Christchurch, the Dorset heathland is interspersed with a rhododendron jungle. The constituency has the highest number of detached dwellings (58 per cent) in England, but here the houses are so far apart that it seems silly to call it a village. It looks a Conservative spot.
At Oakengates, the timbered retirement villa of Bill Brayne, a former consul, Rob Hayward, the Tory candidate, is holding his 33rd 'At Home': a sort of political Tupperware party. The Braynes have invited 15 neighbours to tea while the candidate sells himself. But the group of genteel retired people uses him as a punchbag, with some fairly ill-tempered scrapping over whose turn it is to have a go.
First is Harry Hall, 79, ex-Indian colonial service, who wants to talk about the taking of pensioners' assets to fund their care in homes. 'The public relations of the Tory Government seems to be a failure,' he says. Mr Hayward blames the media.
VAT on domestic fuel comes next ('disgusting]'), then rail privatisation and crime ('For four elections your main thing has been law and order, but you haven't done anything about it] Broken promises, again]').
Mr Hayward, 44, is capable and hard-working - he was formerly MP for Kingswood in Bristol - but the assault gets him flustered. His answers ramble and his line on VAT - that the only things you can rely on in life are taxes and death - goes down like a coffin among his audience. His best moment comes when he confirms that he is in favour of capital punishment: 'Thank goodness for that,' breathes a choleric former civil servant.
Afterwards, with tea poured and gentility restored, the Braynes and friends shake Mr Hayward's hand and complain about the lack of leaflets. Out of earshot, two say they won't be voting. 'This,' Mr Hayward says privately, 'is a sophisticated electorate. You have to talk positively with them. No one said it was going to be easy.'
He leaves to go training with Christchurch Rugby Club. The sleek grey battlebus that bears him away boasts a fax, phones, a PA system. But most useful, perhaps, is the large box of paracetamol on the dashboard.
The Liberal Democrats - ahead by 15 per cent in the local press polls - might be forgiven for thinking it is all over bar the voting. But they have their own headache. The 63.5 per cent of the electorate that voted Conservative in 1992 may be hiding but, as the Liberal Democrat agent, Willie Rennie, says, 'that doesn't mean they're going to come out for us. We have to change the habits of a lifetime'.
The Lib Dems have undoubtedly taken the honours in the campaign's first 10 days but their caution is well-founded. Their task is almost unparalleled. The late Robert Adley gained 39.9 per cent more of the vote than the Lib Dem runner-up in 1992, the second largest Tory majority in percentage terms in the country. This is a larger gap than in the party's most remarkable recent by-election victory, Ribble Valley in 1991. And the electorate here, at 71,469, is larger. If half of Mr Hayward's voters stay at home, he would still win by 5,000.
The swing that gave the Lib Dems victory at Newbury in April would comfortably deliver Christchurch, but things are different here. There is no Liberal tradition: the Lib Dems took Dorset County Council in May but have only one seat locally. All the Conservatives held their seats, taking more than half the vote. Christchurch has not had a Liberal MP since 1906, and at the beginning of the by-election campaign the local party had only 80 members.
When Mr Rennie talks of the habits of a lifetime, he is talking about some very long lives. More than a third of the population is of pensionable age. As a result the campaign's first half has been dominated by the issues of VAT on domestic fuel and prescription charges for pensioners. VAT is on the lips of every pensioner on a fixed income, and the efficient and likeable Lib Dem candidate, a 48-year-old teacher, Diana Maddock, has managed to hang it heavy round Tory necks.
On Friday morning the Chancellor, Kenneth Clarke, came to Christchurch's King's Arms Hotel to say - again, and quite categorically - 'We are not going to introduce prescription charges for pensioners.' However, the Lib Dems have no intention of dropping the issue. One campaigner said: 'The Conservatives can say what they like. We just say to the voters, 'Well, do you still believe the Conservatives?' And the answer invariably is 'No'.'
Mr Clarke went on to a 45- minute closed meeting with local business people. Some of these - including Lillian Jeffris, chairman of the Chamber of Commerce - emerged to profess themselves reassured and ready to vote Conservative; but others were unimpressed. Ian Middleton, the 40-year-old owner of a Christchurch garage business, was one of them: 'I've seen nearly a 50 per cent reduction in my turnover in two years, and I'm lucky I haven't gone under. I was hoping today would give me some extra hope, but Clarke gives me none.'
A life-long Tory, he will now be voting Liberal Democrat - 'like the majority of my friends. We want the Conservatives out of Christchurch. It's not a protest vote. We've seen our businesses systematically destroyed.'
But it is clear that the former Conservative vote is still floating freely. A strong Labour candidate, 32-year-old barrister Nigel Lickley, is not going to give away easily his 7,000 votes.
The Lib Dems have their battle-hardened by-election team (and the computer system that helped them win Newbury) and have recognised the scent of success. Yet Candy Piercy, their national campaigns officer, insists that they still have a huge task. 'We're talking about a tribal shift. We have to convince these people that voting Liberal Democrat is socially acceptable.'