A Bahraini court has provoked condemnation from human rights campaigners by jailing a Shia opposition leader the day after a British government minister visited the Sunni-ruled kingdom to break-ground on a controversial new Royal Navy base.

Sheikh Ali Salman, 49, a Muslim cleric and head of the al Wefaq Islamic Society, has been sentenced to four years in jail after he was arrested in December in case that stirred unrest and prompted condemnation from Iran and the US.

His detention came after he delivered a series of speeches calling for political reform and accountability after his re-election as party leader.

Prosecutors claimed that he promoted the overthrow of the regime and supported attacks that caused the death of 14 policemen, however he was acquitted of these more serious charged, which carried a potential life sentence, and convicted of inciting disobedience and hatred, as well as “insulting an official body”.

The country has been plagued by unrest and political instability since the UK and US supported the Bahraini government’s violent crackdown on dissent during the Arab Spring in 2011.

Two weeks ago the EU Special Representative Stavros Lambrinidis, praised some positive developments in the country, however human rights groups say Sheikh Salman is a “prisoner of conscience” and abuses are continuing unabated in the country.

On Tuesday Amnesty International described Sheikh Salman’s conviction as “another clear example of Bahrain’s flagrant disregard for international obligations” and called for his immediate release.

The court verdict came just one day after British Armed Forces Minister Penny Mordaunt visited Bahrain to attend the official inauguration of a new Royal Navy base in the island kingdom.

Armed Forces Minister Penny Mordaunt joins Bahraini officials and Royal Navy officers to 'open' new Royal Navy base in Bahrain (BNA)

The strategically important base will play host to Royal Navy minesweepers and destroyers, but has been condemned by campaigners as a “reward” for Britain’s silence over continuing human rights violations in the Gulf state.

The base, which was announced by Foreign Secretary Phillip Hammond in December, signals a renewed British commitment to the Gulf. However it has been met with dismay by campaigners, who are seeking a judicial review over the decision.

Sayed Alwadaei, director of advocacy at the Bahrain Institute for Rights and Democracy, said: “The news that Penny Mordaunt was in Bahrain to break ground on the new British naval base came the day before the leader of the opposition and peaceful advocate Sheikh Ali Salman was sentenced to four years in prison. The message to Bahrainis is that the UK cares only about its arms business and not human rights.”

Amnesty International UK’s head of policy Allan Hogarth said: “Cutting the ribbon on a British naval base one day and praising the country’s supposedly ‘ambitious’ reforms on another are odd things for ministers to be focusing on when Bahrain is busy dispatching yet another peaceful critic to jail”.

The visit by the Armed Forces Minister, who cut a ceremonial ribbon at the site of the new base, came the same day as Tobias Ellwood, Minister for the Middle East, was in Bahrain, where he announced a new mutual military agreement between Britain and the Gulf State.

Last month the strength of ties between Bahrain and the British Government were illustrated when Prime Minister David Cameron hosted the Crown Prince of Bahrain at Downing Street.

Andrew Smith of Campaign Against Arms Trade, said: “As the situation in Bahrain worsens its relationship with the UK is only getting stronger. One of the driving factors has been the ever-closer military relationship between the two countries. If the UK is serious about human rights and democracy then it needs to end all military support for regime and stop bolstering an increasingly authoritarian dictatorship.”

Sheikh Salman’s sentencing and closer military ties between Britain and the regime in Sanaa follows a recent Amnesty International report which found that the Bahraini regime continued to “curtail” freedom of expression and that its security forces used “excessive force to disperse protests”.

Bahrain has rejected the report, while the UK Foreign Office says Britain is “working closely” within Bahrain to strengthen “human rights and the rule of law” in the country.

Speaking to The Independent after the sentencing of Sheikh Salman, Mr Ellwood, said: “I am concerned by the verdict and the sentence handed down to Sheikh Ali Salman and I raised this case with the Bahraini authorities during my visit last weekend. I understand that Sheikh Ali Salman can still choose to appeal the court’s decision.”

“The UK Government is supporting the Government of Bahrain in its reform programme, aimed at strengthening human rights and the rule of law, by providing technical assistance in judicial, policing and political reforms. Bahrain has made progress in its reforms, but we are clear more needs to be done, and the UK remains committed to supporting Bahrain in that process.