The expansion of the Paks nuclear power plant will be Hungary's “biggest political error of the 21st century” claimed Bernadett Szel, leader of the small opposition party LMP, on March 22, as she criticised a National Election Committee (NVB) decision to block efforts to hold a referendum.

The inter-governmental deal will see Russia add two new units to Hungary's only nuclear power plant, lending Budapest €10bn towards the €12.5bn project costs into the bargain. The deal was given approval by the EU early this month. Brussels insists much of the power produced must be sold on the open market, however, where prices are far below production costs for a new nuclear plant.

The NVB argued that the five referendum questions submitted by the LMP conflict with “Hungary’s obligations under international agreements,” and were not “clearly worded”. Hungarian law rules out referenda on issues covered by international agreements.

However, the committee’s government-appointed leaders have a history of favouring the ruling party in decision making. Last year the NVB authorized a government sponsored vote on the EU's migrant quotas.

Two high profile opposition referenda applications have made it past the NVB recently - against the Sunday shopping ban and the bid for Budapest to host the Olympics. In both cases, the government chose to back down rather than face defeat in a vote.

The LMP announced a plan for a referendum on Paks 2 in the wake of the collapse of the Olympics bid. In the meantime, the EU gave the deal the green light.

Concentrating so much of the country's output in one location will raise the risk of a terrorist attack, Szel argues. On completion, the plant will produce 60% of Hungary's power.