It has been dubbed “the signature revolution” but the hundreds of thousands of signatures Belarus’ opposition figures have gathered that are part of the application process to stand in the presidential elections are being rejected en masse by the authorities.

Would-be candidates had to submit at least 100,000 signatures on petitions supporting their candidacy in the August 9 presidential elections. But incumbent Belarus President Alexander Lukashenko has been unsettled by the leading opposition candidates gathering 750,000 names in a country with a population of 9mn in an unprecedented show of defiance.

Seven candidates had their applications accepted, including Lukashenko with over two million signatures, as well as the three main opposition leaders: ex-banker and leading opposition candidate Viktor Babariko, popular blogger Sergey Tikhanovsky, both of whom have been arrested, and former diplomat, businessman and Lukashenko aide Valery Tsepkalo.

Now the process of checking those signatures' validity has begun.

“In Belarus election commissions started checking the validity of signatures given in support of presidential candidates. A commission in Gomel became the first one to announce the results. Well, all signatures for #Babariko and #Tsepkalo were deemed invalid. The rest are fine,” Tadeusz Giczan, a London-based academic that follows Belarus, tweeted.

Babariko has been the most popular of the opposition candidates, having collected a record 425,000 names, and was quickly targeted by the authorities, who arrested him on embezzlement and fraud charges on June 18.

Tsepkalo is still at liberty and has run a more conventional campaign with more muted criticism of the authorities but now as the only leading candidate at liberty has also found himself in the cross-hairs.

The Ministry of Internal Affairs announced it has opened an investigation into Tsepkalo at the weekend for “illegal activities” without giving details, spokeswoman for the ministry Volha Chamadanava told Svaboda.

“In order to conduct an investigation, we and the Prosecutor General's Office received materials from a Turkish citizen about the facts of illegal activities of a citizen Tsepkalo. An inspection is being carried out now,” Volha Chamadanava said.

Tsepkalo's team collected more than 200,000 signatures, and he finally submitted around 160,000. So far the election committees in Gomel, Svetlogorsk and Vitebsk regions have rejected all the signatures for Tsepkalo. Reportedly the Frunzensky district in Minsk has also rejected all 65,000 signatures for Babariko and Tsepkalo.

“Out of almost 400,000 signatures submitted by Lukashenko's main rival Viktor Babariko, more than 100,000 were deemed invalid in just one day without any evidence. At this rate, by the end of the week, I won't be surprised if the number of valid signatures will become negative,” Giczan said.

Observers have been surprised at the blatant effrontery of the CEC’s actions. “It's the first time election commissions are acting so boldly, though. Previously they at least tried to give the impression of a democratic process,” Giczan said.

Lukashenko has been visible shaken by the challenge to his authority. Early this week he promised to make changes to the constitution to reflect the popular demands in the next two years, after his re-election.

The author of the YouTube channel "Country for Life" Sergey Tikhanovsky has already been denied registration by the Central Election Commission before the checking process began on the grounds he was in jail, serving a 15 day sentence following his arrest for disturbing the peace and could not submit documents in person. The blogger's wife Svetlana Tikhanovskaya has taken his place and was one of the seven candidates who successfully submitted 100,000 signatures to the CEC.