By Andrew Osborn
LONDON, Sept 6 (Reuters) - Prime Minister David Cameron took the unusual step of listing what he said were Britain's historical achievements and current strengths in a prickly response to a disputed Kremlin slur that his country was a "small island" that nobody listened to.
In St. Petersburg for a G20 summit where possible U.S. military action against the Syrian government dominated the agenda, Cameron chose to focus on comments reportedly made by President Vladimir Putin's spokesman even though the spokesman, Dmitry Peskov, denied making them.
The row underlined deep tensions between Britain and Russia over Syrian President Bashar al-Assad's suspected use of chemical weapons and erupted at a time when Cameron is under pressure to show Britain remains an important global actor despite his failure to convince the British parliament of the need for military action against Assad.
Before travelling to the summit, one of his own senior lawmakers, Liam Fox, a former defence minister, had said Cameron now had "no hand to play" on Syria and many commentators had said Cameron was on the summit's sidelines because of his defeat in the British parliament.
According to the BBC, Peskov told Russian reporters on Thursday that Britain's diplomatic clout was on the wane and that it was "just a small island; no one pays any attention to them".
Peskov was also reported to have quipped about how Russian oligarchs owned large swaths of prime London real estate in Chelsea.
Cameron said he knew the comments had been denied, but spent much of his time responding to them, issuing a lengthy written statement and giving a long answer to a question on the subject at his closing press conference on Friday.
"Britain may be a small island, but I would challenge anyone to find a country with a prouder history, a bigger heart or greater resilience," he said in a statement.
Cameron told reporters Britain had been responsible for the industrial revolution, the TV, the World Wide Web, the Beatles and, incongruously, pop group One Direction.
"Britain is an island that has helped to clear the European continent of fascism," he wrote.
"Britain is an island that helped to abolish slavery, that has invented most of the things worth inventing, including every sport currently played around the world."
His defensive and clearly carefully-planned public relations demarche came as a lawmaker from his ruling Conservative party used Twitter to insult Putin in crude terms over the Russian leader's stance on Syria.
"Insulting people should never have a part in foreign policy," said Cameron of the Tweet. "We should try to maintain good manners and politeness even when under intolerable pressure." (Reporting By Andrew Osborn; Editing by Guy Faulconbridge and Ralph Boulton)