Farmers drove hundreds of tractors into Brussels on Tuesday to protest against the European Union's environmental policies, but the action was shunned by mainstream farming groups who said it did not reflect their members' concerns, reported Reuters.

A few days before the European Parliament election on June 6-9, farmers from the Netherlands, Belgium, Poland and Germany travelled to Brussels to protest against EU green policies that organisers said undermine the competitiveness of European farmers.

"We came from Poland, because we know that the source of our problem is in Brussels. Because we want to change, deeply change, the Green Deal," crop farmer Damian Murawiec told Reuters at the protest in Laeken, in northern Brussels.

It is the latest in a months-long wave of farmers' protests across Europe, where agricultural workers have denounced low food prices, excessive regulation and free-trade deals they say leave them struggling to compete with cheap imports.

The protest was organised by Dutch lobby group Farmers Defence Force and supported by right-wing and far-right groups. With police counting around 500 tractors, it was smaller than previous farmers' protests held in Brussels this year.

"We want Europe to put the Green Deal away because it's not realistic," said Bart Dickens, President of Farmers Defence Force's Belgian branch.

Farmers Defence Force - whose secretary Sieta van Keimpema has described concerns over climate change as "hysterical" - said politicians from Belgian far-right party Vlaams Belang and the right-wing European Conservatives and Reformists group would address the protest in the afternoon.

Europe's biggest farming lobby Copa Cogeca, and farming association La Via Campesina, each told Reuters their members would not participate.

"We reject this attempt by small groups that have no concrete proposals to address farmers' issues to hijack farmer concerns to push their own party interests," a spokesperson for Via Campesina said.

Meanwhile in Poland farmers blocked one border crossing with Ukraine, in what police said was a show of solidarity with protests in Brussels.

"This protest will last three days ... trucks travelling from Ukraine are blocked and 12 trucks are allowed to leave Poland between 8 a.m. and 8 p.m.," said police spokesperson Malgorzata Pawlowska.

All other border crossings with Ukraine were operating normally.

On Thursday two of the largest unions representing farmers in Poland, Solidarity and OPZZ, said that they had no knowledge of the protests.