AMID mounting protests by rebellious teachers the Mexican government has taken a risky gamble. On May 29th, just days before mid-term elections scheduled for June 7th, it “indefinitely suspended” the most important part of its landmark education reform. Officials whisper that they are just trying to ensure a trouble-free day of voting and that they will reverse the move later. If that is true, the government is being deeply cynical. If it is not, it is undermining what some consider its most important policy, and may be breaking the law to boot.

Acting like a guilty schoolboy, the education ministry issued a curt, 33-word statement saying it was suspending examinations of teachers. The exams were due to take place for the first time in July as part of the education reform approved by Congress in 2013. For two years, President Enrique Peña Nieto’s government has argued that the tests are the lynchpin of the constitutional reform, because they will eventually weed out bad teachers from Mexico’s woefully underperforming schools. The explanation for this sudden change? There were "new elements to consider", the statement said.

Failing schools pose a big challenge to President Enrique Peña Nieto’s vision for modernising Mexico Officials later elaborated that the announcement was an attempt to placate teachers from the CNTE, their most radical union, who loathe the notion of testing, and have threatened to boycott the elections—to choose 500 congressmen, nine governors and hundreds of mayors—in the southern states where they hold sway. "It’s temporary," an official said, adding that there was a "99% chance" that the move would be reversed after the election. But the CNTE saw straight through the ploy. Instead of quieting down, it has stepped up its protests. On June 1st it launched a indefinite strike that has kept more than 1m children out of school. Its members have occupied election offices in the southern state of Oaxaca, burnt tens of thousands of ballot papers and seized petrol stations and threatened airports. One of its main demands is that 43 teacher-trainees who went missing last year in the neighbouring state of Guerrero be returned alive to their families, though the government insists they are dead—murdered last year by police in the pay of drug traffickers. The union also wants the whole education reform abolished. "We knew from the start that the promise about the evaluations was a temporary one," says Mohamed Otaqui, the teachers’ spokesman in Oaxaca, where the CNTE is most militant. He added that unless the government agreed to all their demands in the next few days (including the Lazarus-like return of the 43), "We will stop the elections from taking place in Oaxaca." Besides the lingering prospect of electoral disruption in the south, the government faces accusations that it is breaking laws that it enacted. In suspending the tests, even if only temporarily, it angered the National Institute for Education Evaluation (INEE), an autonomous body that was given a constitutional mandate as part of the education reform. It accused the education ministry of violating the constitution, invading its area of authority and threatening its autonomy. A group of NGOs and other institutions linked to the INEE have given Mr Peña until the day after the elections to lift the suspension.

But even if he does, the move will be damaging, analysts say. It casts doubt over the autonomy of other independent bodies set up by Congress to ensure full implementation of the 11 reforms promoted by Mr Peña since 2012, such as the new energy and telecoms regulators. "It generates uncertainty about the rest of the reforms," said GEA-ISA, a polling firm, in a report on June 2nd. It could also encourage other interest groups to stand up against the reforms, it added.

The most ambitious of those, bringing private investment into the oil industry, appears to be going smoothly. But even adventurous oil investors braving Mexico for the first time will be unnerved to see the government so cavalier about enforcing laws that it claims most of the credit for.