Junior foreign minister Hugo Swire said Imran's conviction on terrorism charges "raises worrying questions about freedom of speech, the rule of law and the government's commitment to democracy."
Maldives yesterday sentenced Imran, the leader of the country's main Islamist party, to 12 years in jail.
The opposition Adhaalath Party (AP) leader was charged under a 1990 anti-terrorism law for allegedly inciting unrest during an anti-government rally last May on the capital island Male.
His imprisonment comes 11 months after the highly controversial jailing of the country's main opposition leader Mohamed Nasheed, who last month obtained prison leave to undergo urgent surgery in London.
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"I urge the government to work towards greater judicial independence and to restore confidence in democracy," he said in a statement on the government's website.
"The government should release all political prisoners, end politically motivated trials and ensure all-party dialogue is genuine and inclusive," he added.
President Abdulla Yameen is under intense international pressure to free Nasheed, the country's first democratically elected president.
The tiny nation of 340,000 Sunni Muslims has been gripped by political turmoil, damaging to its reputation as a luxury holiday destination, since Nasheed was toppled four years ago in what he claimed was a coup led by mutinous police and troops.