Legislators poised to vote on deployment of troops in Iraq and Syria as pressure piles on Turkey to join anti-Isis coalition

Amid mounting pressure to take a stance against the Islamic State (Isis), Turkish legislators will vote on Thursday on a motion to authorise its forces to be deployed in Iraq and Syria in the case of a threat to national security.

The main opposition Republican People’s party and the pro-Kurdish People’s Democracy party are unlikely to support the motion. The mandate, submitted on Tuesday by the prime minister, Ahmet Davutoğlu, also allows for foreign troops to transit through Turkey and calls for the establishment of a so-called security zone of up to 20 miles inside neighbouring Syria, in what is being cast as a pivotal moment in a war threatening three countries.

But hours from the parliamentary ballot, doubts remained over Ankara’s intent, with some observers and MPs suggesting the proposed mandate merely rubber-stamps an existing policy and has been dressed up to look like a decisive shift. Kurdish groups in Turkey and Syria also accuse the ruling Justice and Development party of wanting to use the buffer zone as a means to occupy Kurdish-Syrian enclaves across the border.

Others, however, believe President Recep Tayyip Erdoğan is determined to move against Isis, but will do so only if pressure on the Syrian leader, Bashar al-Assad, is also increased.

Also central to Turkish calls for a buffer zone is the fate of the tomb of the founder of the Ottoman Empire Osman I, marked as Turkish territory by the 1921 Turkey-France border accord and now protected by Turkish troops on Syrian soil near the town of Manbij.

For the past year, the tomb has been surrounded by Isis forces, who have faced up to about 50 Turkish special forces troops that were deployed more than six months ago when security concerns moved Ankara to recall the comparatively inexperienced conscripts that had been guarding the shrine.

While Isis units have not advanced, they have sprayed graffiti over checkpoints leading towards it. In March, Isis warned in an internet message that they would “raze the tomb” but no such attack has since been launched. The tomb of Osman has been a ready barometer of the accommodation reached between Turkey and Isis since it first gained a foothold in Syria and then Iraq.

It is also symbol of a relationship now at a crossroads, with Erdoğan suggesting repeatedly in the past week that the country’s military would get directly involved, possibly with ground troops.

Kurds on both sides of the border have warned that such a move might imperil the ongoing peace process between the Turkish government and the outlawed Kurdistan Workers’ party, with Cemil Bayik, co-chair of the Kurdish political umbrella organisation KCK, saying it would spell the end of the peace efforts.

“The [peace] process would be over, war would restart,” Bayik told the Turkish daily Radikal. “Because a buffer zone is directed against us. We cannot negotiate peace with a [state] that tries to take our gains in Rojava (Western Kurdistan – Syria) from us. That would be treachery against our people.”