The sex video that could determine Turkey's future

"This is a final warning. We do not want to release tapes that we have in our possession," announced a letter that appeared on Farkli Ulkuculuk (Different Idealism), a Turkish website, on May 13. "Hell will be unleashed if we release [more] recordings … Do not force us to do so."

The letter's intended addressee, Devlet Bahceli, the leader of Turkey's far-right Nationalist Movement Party (MHP), certainly had reason to worry. Just a few weeks earlier, the Different Idealists - their real identity still unknown - had released a series of secretly recorded videotapes showing deputies from Bahceli's party cavorting with young women, including, allegedly, a 16-year-old. Ten MHP representatives have since resigned from their posts.

Until the tape scandal, pretty much the only thing worth speculating about in the run-up to tomorrow's Turkish elections appeared to be the ruling Justice and Development Party's (AKP) possible margin of victory. Not anymore. Although no new tapes have appeared, and although Bahceli himself has refused to resign, all eyes are now on his MHP. Its performance at the polls might determine Turkey's political landscape for the next five years, if not more.

At first sight, it's difficult to understand why. The AKP, which has not lost a single election since 2002, is expected to receive nearly 50 per cent of the vote. A year ago, its main challenger, the Republican People's Party (CHP), appeared capable of putting up a respectable fight. Under a new leader, Kemal Kilicdaroglu, the CHP parted ways with its antediluvian old guard, toned down its fanatical defence of French-style secularism, and focused on more pragmatic concerns like fighting corruption and unemployment. It also began to make relatively successful overtures to Kurdish voters, who have long refused to give the party the benefit of the doubt.

Kilicdaroglu, without a doubt, has been a breath of fresh air for his party. Still, he is no match for Prime Minister Tayyip Erdogan and the AKP. On Sunday, the CHP will probably be content to go home with 30 per cent. The MHP is in even more dire straits, its support having slipped into the single digits, at least according to some polls. The stage therefore appears set for a landslide victory for Erdogan's AKP. So why is all the attention on the MHP?

The reason has to do with Turkey's extraordinarily high electoral threshold. Denying parliamentary representation to parties that fail to secure a certain percentage of the popular vote is far from unusual. Where most democratic countries have minimum thresholds ranging from two to five per cent, Turkey's is a whopping 10 per cent, the highest in Europe.

For years, the threshold - true to its intended purpose - prevented Kurdish nationalist parties from entering parliament, frustrating the hopes of many of Turkey's 12-15 million Kurds to have a voice at the national level. (In the last elections, Kurdish candidates managed to sidestep the threshold by campaigning as independents.)

The Kurds are far from the only group to have suffered. By shutting smaller parties out of parliament, the 10 per cent rule has regularly disenfranchised large chunks of the Turkish electorate. In 2002, for example, the AKP won two-thirds of all parliamentary seats with only one-third of the popular vote, while the CHP won one-third of seats with one-fifth of the vote. The votes of the remaining 45 per cent of Turks - their parties of choice having failed to clear the threshold - were effectively rendered void.

Until recently, the MHP seemed assured of just under 15 per cent of the vote. Now, however, beset by the sex scandal, the party is expected to fight tooth and nail just to pass the 10 per cent mark. There's nothing that Erdogan would like more than to see it fail. If the MHP comes up short, Erdogan's AKP may find itself with enough votes in parliament to rule unopposed - and to push through its pet project, a new constitution. Winning 330 seats (out of a total of 550) would allow the AKP to call a referendum on the new charter; 367 seats would allow it to change the constitution without a referendum.

Erdogan has pulled out all the stops to ensure that the MHP stumbles. In the past few months, he has reached out to the MHP's base constituency, brandishing his own nationalist credentials and toughening up his rhetoric, especially regarding the Turkish state's troubled relationship with its Kurdish minority.

The same man who once acknowledged that the state had mishandled the Kurdish issue and would now have to face it head-on - and who launched a "democratic opening" in 2010 to give the Kurds new cultural and language rights - recently claimed that "there is no longer a Kurdish question in this country".

According to Bahceli, the prime minister has now taken to punching below the belt. In May, the nationalist leader accused the AKP, acting in tandem with a powerful Islamic movement, of procuring and leaking the sex tapes. The operation, says Bahceli, was done with one goal in mind: to drain away the MHP's support and ensure that it stays out of parliament. (To date, the identity of the person or persons who released the sex tapes remains unknown. In another twist to the story, the Turkish internet has recently been abuzz with rumours that a new tape - this time, featuring a female AKP politician - would soon be released.)

Many pro-government commentators claim that an absolute majority is exactly what Erdogan needs to implement a truly democratic constitution, replacing the one bestowed on Turks by a military junta in 1982 after a coup d'état. It is only by marginalising the opposition, they argue, that the next AKP government can implement new reforms, lift remaining restrictions on free speech, resolve the Kurdish issue, and revive the stalled negotiation process with the European Union. Others, however, mindful of Erdogan's increasing authoritarian streak, fear that a constitution drafted without bipartisan support will further entrench the AKP's hold on power, particularly if it opens the way for Erdogan to implement a presidential system.

Erdogan has made no secret of his ambition to become president when his term as prime minister runs out. If he succeeds, he may remain in power at least until the year 2021. The AKP government's recent crackdown on critics in the media has already triggered accusations of Turkey's "Putinisation". If Erdogan hammers through a constitution that yields nothing to the opposition and only cements his party's dominance, such comparisons - far-fetched as they might seem for the time being - could soon begin to multiply.

Piotr Zalewski is a freelance journalist living in Istanbul