The Czech Republic holds a parliamentary election on 8-9 October. Opinion polls put Babis' centrist ANO party ahead of rivals but some show him falling short of partners to form a majority government, which could hand power to a coalition between the main opposition centre-left and centre-right groups.

On the campaign trail, accompanied by Orban, Babis stressed how he and the Hungarian leader had blocked the European Commission's plan to distribute asylum seekers around the bloc under a quota system following Europe's 2015 migration crisis.

"We push for our national interests together" in the EU, Babis said after introducing Orban at a joint news conference in the northern town of Usti nad Laben, where the Czech leader heads the ANO party's ticket.

Orban also praised their countries' close cooperation as well as the Czech Republic's economic success.

"We in Hungary are ready to maintain close, friendly, sober cooperation with Andrej Babis's government," said Orban, whose right-wing Fidesz party has governed Hungary since 2010, often clashing with Brussels over immigration and reforms of the media, the judiciary, academic institutions and NGOs.

Earlier this week, the Czech government agreed to send 50 police officers to help guard the Hungarian border with Serbia, which Babis also visited last week.

ALLIES

Babis, a billionaire businessman, has grown increasingly positive about cooperation within the central European Visegrad Group and particularly with Orban in the past few years, despite the EU's concerns over the rule of law in Hungary.

The Czech Republic did not join the majority of EU states this year in signing a letter protesting against Hungarian legislation banning the use of materials seen as promoting homosexuality and gender reassignment at schools.

One of the two main opposition coalitions contesting the Czech election, the Pirate Party/Mayors, attacked Babis over his ties with Orban.

"Viktor Orban shifted Hungary from democracy to autocracy over the past 10 years," its chief Ivan Bartos said on Facebook.

"He liquidates free media, liquidates the opposition, free enterprise, spies on journalists... Such policy is the model for Andrej Babis."