By Madeline Chambers

LONDON, March 15 (Reuters) Britain's declaration that it will support efforts by Iranians to win more freedom marks a shift in emphasis in London's relations with Tehran and is based on a recognition that nuclear talks have reached a dead end.

But Foreign Minister Jack Straw's statement this week that the Islamic state is heading in the wrong direction, and that its people deserve better, stops short of Washington's increasingly aggressive stance, say diplomats and analysts.

In a speech seen as more confrontational than usual, Straw also urged world bodies to boost the information flow to Iran.

The aim, diplomats say, is to widen the narrow focus on the nuclear issue which has dominated dialogue since 2003. Britain now wants to encourage Iranians to alter their country's course.

Straw stressed how Iran could benefit from cooperation with the world, citing potential gains for the world's fourth biggest oil exporter from foreign investment.

''We're fed up with it looking as if we are just worried about the nuclear issue,'' said a British diplomat. ''We take Iran seriously and we have no choice but to deal with them.'' Relations with Iran have deteriorated since President Mahmoud Ahmadinejad took office last year and hit a low point when London accused Tehran of assisting militants in Iraq.

But the dispute over Iran's nuclear progamme has been top of the agenda. The United States and European Union suspect Iran wants to build an atomic bomb while Tehran insists it wants nuclear technology only to generate electricity.

Talks with Britain, France and Germany broke down when Iran restarted sensitive nuclear work this year. It now risks censure from the UN Security Council, which can impose sanctions.

NUCLEAR DRIVE IRREVERSIBLE? Senior British officials say the EU trio's main achievement may have been to delay Iran's ability to make nuclear arms and some analysts argue that efforts to prevent this cannot work.

''You have to realise you are not going to stop Iran having nuclear advances. The nuclear argument cannot be won on its own terms,'' said Iran expert Ali Ansari of St Andrews University.

Straw excludes any military option and says Security Council action must be ''incremental and reversible'', but diplomats see scant prospects that Iran will back down on the nuclear issue.

The best hope may be change inside Iran, say diplomats.

''(Straw's) speech sent a clear signal -- let's try to influence and change behaviour in Iran rather than talk about military options,'' said lawmaker Mike Gapes, chairman of parliament's influential foreign affairs committee.

''The best approach in the long term is to give Iranians a window to the world, either through the Internet, TV or radio.'' But Straw's remarks could be interpreted -- certainly by Iranian leaders -- as wanting to foment dissent.

Iran's Foreign Ministry spokesman Hamid Reza Asefi said Straw had ''miscalculated'' and was ''unwise'' to say Iran was moving the wrong way, the ISNA students news agency reported.

His speech had echoes of Washington's more hostile approach and came just a month after the United States outlined plans to expand television broadcasts to its old enemy Iran.

Secretary of State Condoleezza Rice has also asked Congress for dollars to help open up its tightly controlled society.

However, Britain is taking a subtler line, analysts say.

''Britain wants regime change but they want it to be done differently from the U.S,'' said the Centre for European Reform's Daniel Keohane. ''Britain says it has to be done from within.'' Reuters HS BST1812