Jaroslaw Kaczynski said it was vital to head off the 'break-up' of the EU as he addressed a congress of his conservative Law and Justice party in Warsaw

Poland's rightwing leader has become the latest political figure to wade into the Brexit row calling on the European Union to 'reach out' to Britain and 'give it a chance, a chance of returning'.

Jaroslaw Kaczynski, who has a strong reputation as a eurosceptic, said it was vital to head off the 'break-up' of the EU as he addressed a congress of his conservative Law and Justice party.

He said: 'We have to reach out (to Britain). We have to give it a chance, a chance of returning.'

Kaczynski, 67, who was speaking in in Warsaw, did not give any details about what he meant but insisted his ideas were gaining traction elsewhere, particularly among Germany's Social Democrats.

The rightwing chief had earlier proposed holding a second in-out referendum in Britain to try to encourage the country to stay.

Britons voted on June 23 by around 52 to 48 per cent to pull out of the EU - a decision that has unleashed a deep domestic political crisis and what experts fear will be the start of a recession.

Speaking today, Kaczynski also attacked proposals from leading EU countries that have taken a firm line with Britain and told it to start the exit process as soon as possible.

'The initial proposals from these big countries encourage the break-up of the Union.

'We cannot stand idly by and let the most powerful ones carry on like this... We cannot allow the Union to fall apart,' Kaczynski said.

'Britain is being treated arrogantly today, which is a hysterical reaction,' he added.

Kaczynski holds no cabinet post but as a former prime minister and co-founder of the PiS has a reputation of powerbroker.

Around 800,000 Poles live in Britain, where they headed after the EU's 2004 'Big Bang' expansion to former Communist states in eastern and central Europe.

Poland's government swept to power in elections last October on an anti-migrant and populist spending platform.

Like Britain, it is opposed to European federalism, although surveys say the country's population is very strongly pro-EU.

On May 7, around a quarter of a million people attended a rally in Warsaw in support of the EU and in protest at perceived attempts by the government to undermine democracy, according to estimates from city hall.

Slovakia's prime minister Robert Fico (pictured at a government meeting on June 30) earlier claimed that nobody had the right to be angry with the UK for opting for Brexit, blaming European policy for the Leave vote

Kaczynski is the latest political figure in Europe to come out in support of Britain.

Slovakia's prime minister earlier said nobody had the right to be angry with the UK for opting for Brexit, blaming European policy for the Leave vote.

Robert Fico criticised both France and Germany saying the EU's future cannot be decided by just one or two countries as Slovakia took control of the rotating presidency of the bloc.

Mr Fico admitted there are elements of the bloc that make it unattractive to some countries.

He said: 'The British people have reacted to European policy. Nobody has the right to be angry with the British voters.'

Meanwhile, Slovakian foreign minister Miroslav Lajcak added: 'There's a feeling among member states that sometimes they agree something and then the Commission comes up with the proposals that don't reflect that.