Prime ministers of the Visegrad group countries, (left to right) Czech Republic's Prime Minister Bohuslav Sobotka, Hungary's Prime Minister Viktor Orban, Poland's Prime Minister Beata Szydlo and Slovakia's Prime Minister Robert Fico | Janek Skarzynski/AFP via Getty Images Brussels takes on (most of the) Visegrad Group over refugees Hungary, Poland and the Czech Republic to face sanctions for failing to take part in relocation scheme.

The European Commission is this week expected to launch infringement proceedings against Poland, Hungary and the Czech Republic over their refusal to join in with the EU's refugee relocation scheme, diplomats said.

In summer 2015 EU member countries agreed to relocate 160,000 refugees across the bloc and their decision is legally binding.

However, Poland and Hungary haven't taken in a single refugee between them, and they openly oppose the mandatory nature of the scheme. The Czech Republic, which holds elections in October, took in just 12 last year and none this year, with the government last week saying it would withdraw from the scheme because of security concerns.

Slovakia — the fourth member of the Visegrad Group of Central European countries — has relocated just 16 refugees out of the 902 it was supposed to take. However, it will not be sanctioned as the Commission is only taking action against countries that have not made pledges to take in refugees in the last 12 months.

The Visegrad Group has relocated 28 refugees in total out of a combined quota of 11,069.

Brussels' decision to take action could backfire by widening the gap between the West and East in the bloc at a time when relations with Poland and Hungary are at a low point because of spats over the rule of law and respect for democracy.

Wary of the consequences, the Commission is treading carefully. The infringements, likely to be announced Wednesday, will be part of a package of about 140 measures, a Commission official said — and it has already forewarned some of those involved. Commission President Jean-Claude Juncker informed Czech Prime Minister Bohuslav Sobotka in Prague last week that action was on the cards, a diplomat and an official said.

The countries that were not informed of the Commission's intentions in private could simply read Juncker's interviews, such as the one he gave to Der Spiegel, published Friday, in which he said: “I am for it [launching infringement proceedings] — not to make a threat, but to make clear that decisions that have been made are applicable law, even if you have voted against it.”

The Commission also has one eye on a pending court case. Hungary and Slovakia have challenged the mandatory nature of the relocation scheme at the European Court of Justice, and an advocate-general of the court will issue an opinion on July 26 (in most cases, the eventual court ruling matches the advocate-general's opinion).

One of the main obstacles against launching infringement proceedings was the effect it could have on changing the EU's asylum rules. A deal was supposed to have been reached by this month, but talks are deadlocked.

Ministers from the three Visegrad nations are ready for the clash. The Commission's actions "are of political rather than of legal nature,” Hungarian Foreign Minister Péter Szijjártó said Monday.

"Security policy is a national, not European, competence,” Polish Interior Minister Mariusz Błaszczak said Monday, describing any action as "groundless."