They achieve notoriety through a mix of combustible characters and often ugly protests, yet are kept on the political margins due to infighting and ill thought-out policies. But, next month, at a meeting in Denmark, some of Europe's most notorious right-wing groups will meet for the European Counter-Jihad Meeting.

Those attending could witness the birth of a right-wing movement, the European Defence League – and the beginning of a dangerous new phase in extremist politics.

Representatives from defence leagues in Denmark, Sweden, Norway, the USA, Italy, Poland and Finland are due to attend, along with the anti-Muslim groups Stop Islamisation of Europe, Stop Islamisation of the World and the far-right European Freedom Initiative. It is feared the new umbrella organisation could co-ordinate right-wing activities across Europe while politicising and unifying disparate groups. The idea, which is being championed by the English Defence League (EDL), could be modelled on the European Union – with delegates from participating countries meeting regularly.

Weyman Bennett, spokesman for pressure group Unite Against Fascism, said the meeting in Denmark's second city, Aarhus, was the first meaningful meeting of such groups – which were looking at the EDL model and to mimic successful right-wing political parties in Eastern Europe, some of which have made it to government. He said: "The Euro-leagues are a new danger. We should not forget that it was the Norwegian Defence League that gave us [Anders] Brevik. The growth of a Euro-league in a time of economic crisis threatens to resurrect fascist street armies such as those that destroyed European democracies in the 1930s. The development of this network allows fascists and right-wing populists to share ideas, finance and experience in a way that should worry us all."

Mr Bennett added the groups would be using the euro crisis as a way to pull in new members, particularly from the middle classes.

He added: "We used to have a number of disparate groups. Now we are moving to a stage where we have fewer groups but they are more organised and sophisticated."

Some 50 EDL leaders – whose members have been involved in violent clashes with anti-fascist groups in the past – will travel to the meeting. "This is the first proper European Defence League meet. We have been building bridges for the last two years and this is going to be the launch pad," said Stephen Yaxley-Lennon, the leader of the EDL, who is also known as Tommy Robinson.

He added the leader of each national defence league would sit on a panel and would meet "every three to four months". He said: "We will discuss tactics. Each country's delegates will get time to describe the problems they have. We will try to pool resources. For example, if another defence league wants to run a demonstration in their own country, they are unlikely to get as much media interest as if we were involved, so we would go over there and lend some support."

Dr Matthew Goodwin, an expert on the far-right at Nottingham University, said a Continent-wide far-right alliance would help extremist groups organise demonstrations, which carry the possibility of violence and provide access to better-resourced and organised groups in eastern and central Europe.

He said: "The strategy is to organise large marches for the media attention and to provoke anti-fascist and Muslim groups, as well as the local population. Wherever these movements go, there is a possibility of violent clashes. With the EDL, there are question marks over where the movement is heading, if not towards elections. This would be an indication of where it sees itself going."

Dr Goodwin added that, historically, the far-right has often tried to build alliances on the Continent. "If there is anything the Breivik experience taught us, it is that the European-level movements, which share ideas and resources, are very dangerous."

Farooq Murad, secretary general of the Muslim Council of Britain (MCB) said the move was "worrying". He added the MCB was trying to bring together Muslim groups to counter an increase in Islamophobia.

Last year, Mr Yaxley-Lennon announced that negotiations to set up a political wing of the EDL were at an advanced stage. An alliance with the far-right British Freedom Party was discussed and Mr Yaxley-Lennon said he hoped to stand candidates in the next round of local elections. That deal has not yet been concluded and it is thought that it has met with some resistance among the EDL's grassroots.