By Paul Taylor
LONDON, Jan 21 (Reuters) - Prime Minister David Cameron is leading Britain into a minefield in seeking to renegotiate its terms of membership of the European Union. His gamble could easily end in a bust.
Cameron postponed a landmark speech on Europe, due to have been delivered in Amsterdam last Friday, because of a hostage crisis in Algeria, but he had already disclosed the thrust of his plan to try to change London's relationship with the EU.
Extracts from the undelivered speech released by his office show he planned to say Britain would "drift towards the exit" unless the EU reformed itself. That sounded reminiscent of a 1930s British newspaper headline: "Fog in the Channel, the continent cut off".
The excerpts did not mention a referendum, which Cameron has indicated he would hold later in the decade after negotiating a "new settlement" with Europe.
His strategy is bound to open a prolonged period of uncertainty in which events could put his preferred option -- a looser version of full British membership -- out of reach.
First, all Britain's 26 partners must be willing to negotiate on Cameron's agenda, which despite some expressions of goodwill is by no means a given. Euro zone states may prefer to press ahead with closer integration without reopening the EU treaties, or refuse to unravel past agreements.
Second, they would have to be confident in the prime minister's ability to win a national vote and make an agreement stick over the long term to justify significant concessions. But many EU officials are not convinced Cameron's Conservatives will win a 2015 general election. There is no incentive to give him more than polite sympathy until then.
Third, EU partners would have to be able to win the consent of their own voters or parliaments for any special deal with Britain that could involve watering down European social and employment rights and giving London a lock on EU financial services legislation.
Many are worried that an a-la-carte Europe would lead other countries to demand opt-outs.
Finally, the whole process must proceed free from the kind of unpredictable clashes, political accidents or media scares that have dogged London's ties with the EU for decades.
No rational gambler would bet on all those stars staying aligned. Despite Cameron's declared intention of keeping Britain in Europe, you don't have to be an astrologer to see how this could end in divorce.
Britain has renegotiated its terms twice since it joined the European Economic Community in 1973, yet it remains a reluctant, semi-detached and often obstructive member.
Prime Minister Harold Wilson won some cosmetic trade concessions that were endorsed in a 1975 referendum on staying in. Margaret Thatcher secured a large, permanent annual rebate on London's EU budget contribution in 1984, which remains a source of resentment for many partners to this day.
Despite obtaining opt-outs from Europe's single currency and the Schengen zone of passport-free travel, the British public and Conservative politicians have turned ever more hostile to the EU, depicted in much of the British media as a malevolent, meddling foreign bureaucracy.
With the exception of a couple of short-lived honeymoons during the construction of the European single market in the mid-1980s and the launch of a European security and defence policy in the late 1990s, relations have always been fraught.
It is hard to recall that 15 years ago, Prime Minister Tony Blair was publicly proclaiming his intention to lead Britain into the euro as soon as economic conditions were right.
For most of the time, successive British governments have fought tooth-and-nail to thwart or slow moves towards "ever closer union", the goal enshrined in EU treaties since 1957.
No wonder that despite their leaders' public pledges of support for keeping Britain in, many European officials and diplomats privately wonder if the EU would not be more united and freer to advance if the British could be managed out.
"There's a feeling that it might be best to use the next inter-governmental conference (on EU treaty reform) to organise the UK's exit," a French official said, speaking anonymously because he was expressing a personal view.
Former European Commission President Jacques Delors, who clashed frequently with Thatcher, has suggested publicly Britain should leave the Union and be offered "a different form of partnership" based on the European Economic Area.
Officially, no EU government takes that line. But imagine some of the events that could intervene to change the game.
What if the UK Independence Party, which advocates complete withdrawal, were to win next year's European Parliament elections in Britain or outpoll Cameron's Conservatives despite his renegotiation and referendum pledge?
That could force the prime minister to ratchet up demands to repatriate powers from Brussels to lure back anti-EU protest voters in the 2015 general election. It could also undermine EU partners' belief that any concessions would be sufficient to secure a "yes" vote in Britain.
If, confounding opinion polls, Scotland votes to leave the United Kingdom in a referendum next year, where would that leave the more Eurosceptical English?
Scottish First Minister Alex Salmond has said Scotland would want to stay in the EU, but Brussels lawyers say a seceding Edinburgh would likely have to apply from scratch, negotiate membership terms and win unanimous acceptance to join.
Other factors could intervene to complicate negotiations.
A dispute over mad cow disease in Britain in 1996 caused a crisis between London and its partners, with the British boycotting EU business for months in anger at a ban on beef exports to the continent.
Now, Britain may clash with Brussels over tighter financial regulation sought by the euro zone countries.
Another serious risk is that public expectations of change in Britain's EU membership terms grow unrealistically high and the deal that Cameron is able to negotiate is dismissed by Eurosceptical politicians and media as a sham or a joke.
Even if none of these landmines is detonated, there remains the strong possibility that voters given the first choice in a generation to vote "no" to the European Union choose to do so.
Experience with referendums in France, the Netherlands and Ireland shows voters may cast a protest vote against an unpopular government, or simply express a general dislike of Europe, regardless of the question they are asked. (Writing by Paul Taylor, Editing by Mark Trevelyan)