More than 30 leading public figures in the Czech Republic have signed an open letter urging the UK to vote to stay in the EU in next month's referendum.
The letter says the UK plays a key "balancing role" in European politics and a British exit from the EU "would be disastrous".
It is addressed to the Czech-born British playwright, Sir Tom Stoppard.
The signatories include Cold War-era dissidents, supermodel Eva Herzigova and renowned conductor Jiri Belohlavek.
The list is topped by Michael Zantovsky, a former Czech ambassador to London who was spokesman for the late Vaclav Havel, the man who led the 1989 Velvet Revolution that swept the Soviet-backed communists from power. Mr Zantovsky now runs the Vaclav Havel library.
Havel's brother Ivan is also a signatory, as are Cardinal Dominik Duka, Archbishop of Prague, and former gymnast Vera Caslavska, who won seven Olympic gold medals.
The Czech letter speaks of the close historical ties that bind Britain to Bohemia, a common Celtic heritage, medieval royal marriages and the Czechoslovak fighter pilots who served in the RAF in the Battle of Britain.
"Britain... has played a balancing role in European politics, effectively preventing any large European power from playing a hegemonistic role," the letter says.
Trade and economy
How trade and the UK's economy are affected by membership of the EU.
What the leave and remain sides are saying about trade and the economy in the #EUref campaign
About half of UK overseas trade is conducted with the EU
The EU single market allows the free movement of goods, services, capital and workers
Trade negotiations with other parts of the world are conducted by the EU, not individual member states
UK companies would be freed from the burden of EU regulation
Trade with EU countries would continue because we import more from them than we export to them
Britain would be able to negotiate its own trade deals with other countries
Brexit would cause an economic shock and growth would be slower
As a share of exports Britain is more dependent on the rest of the EU than they are on us
The UK would still have to apply EU rules to retain access to the single market
EU referendum issues guide: Explore the argumentshttp://www.bbc.co.uk/news/uk-politics-eu-referendum-36027205http://www.bbc.co.uk/news/special/2016/newsspec_13606/content/iframe/english/index.inc.app.htmlExplore all the issuesChoose an issue:What both sides are sayingAll issuesMain viewsShare this pageEU referendum issues guideWhat the leave and remain sides are saying in the #EUref campaign
But it also acknowledges that "many Europeans, in the East and in the West, are frustrated with the decreasing ability of the EU to cope with the current problems".
It says Brexit would leave the UK isolated, "stranded in the middle of the Atlantic", and argues that Europe has gained from the British "democratic institutions, entrepreneurial spirit, common sense and pragmatic approach".
However, the signatories stress that the plea to the UK is non-political - and only one of them is a serving politician.
The Czech Republic and three of its ex-communist neighbours - Hungary, Poland and Slovakia - are in dispute with their EU partners over refugee policy.
The four - together called the Visegrad Group - object to a European Union plan to distribute refugees more fairly across the EU. The four argue that they are ill-suited to integrate migrants, especially Muslims from outside Europe.
There is also a strong strain of Euroscepticism in Czech society - and support for EU membership amongst the Czechs has plunged in recent years.
Some Czech leaders, including President Milos Zeman, have spoken out against other EU policies, besides migration.
Mr Zeman says the EU should lift its sanctions on Russia, imposed over the March 2014 Russian annexation of Crimea, internationally recognised as part of Ukraine.
His predecessor Vaclav Klaus was staunchly Eurosceptic, arguing that the behaviour of EU officials reminded him of the Soviet bloc.