The European Court of Human Rights in Strasbourg ruled that Denise Matthews, 24, should be given a vote because people in Gibraltar, a British Overseas Territory, are affected by European Union laws.

The ruling now opens up the prospect of the law being changed to allow all British nationals in Gibraltar to vote.

Ms Matthews, who is British but lives in Gibraltar, had applied to be registered as a voter in the European elections in April 1994. She was told that Gibraltar was not included in the franchise for those elections.

The court said she was denied her right under the European human rights convention to "vote to choose the legislature".

Britain currently does not grant residents of the colony a say in choosing MEPs because it does not consider the European Parliament to have the same status as a "legislature" as the parliament in Westminster.

'No power' - Foreign Office

Reacting to the news, the Foreign Office insisted that the UK had never objected on principle to Gibraltarians having voting rights in European elections, and did not want to deprive them of their democratic rights.

"The long-standing position of successive governments has reflected the fact that it is not in our power unilaterally to extend the franchise," said a spokeswoman.

But she added: "The judgment greatly strengthens the basis on which to approach other member states. The government will be initiating consultations in Brussels on the way forward."

'Travesty of democracy'

The Conservative spokesman on home affairs, James Clappison, welcomed the court judgement.

He said: "It is a travesty of democracy that - alone in Europe - the people of Gibraltar can't elect an MEP to represent them in the European Parliament.

"They have to obey the bulk of laws made in Brussels, so why shouldn't they have a say in making them?"

Extending the vote

Officials at the Court of Human Rights said the judgment implied that the right to vote in European Parliament elections should now be extended to all British citizens living in Gibraltar.

"The issue is that EU legislation directly affects people in Gibraltar and they therefore should have a right to vote," said an official.

Last June, the people of Gibraltar presented a petition to the House of Lords in support of their demand to be allowed to vote in elections to the European Parliament.

The petition called for changes to the European Parliamentary Elections Bill "to enfranchise British and other European Union nationals resident in Gibraltar".

The government is expected to resist the amendments on the grounds that any such change to the franchise would require the consent of other EU countries, including Spain, which has a long-standing claim to Gibraltar.

With tensions currently running high on Gibraltar's sovereignty, Spain may veto any move which further ties the colony's residents into the British electoral system.