Rehman Chishti MP is Member of Parliament for Gillingham and Rainham and a former advisor to Benazir Bhutto, former Prime Minister of Pakistan.

Civil war has been raging in Syria for more than four years now. Hundreds of thousands have been killed, and eleven million have fled their homes.

The government of President Bashar al-Assad still clings onto power and Daesh, also known as ISIS/ISIL, has emerged as the key security threat both in the wider Middle East and on the streets across the world, whether it is New York, London, Paris or Riyadh.

Assad tacitly encourages Daesh, both to threaten the moderate opposition and knowing that, with great reluctance, the international community would back him over those murderers if no other alternatives existed.

As a second round of diplomatic talks begins in Vienna this weekend, the international community must address the issue of Assad, who cannot be allowed to stay.

We must not let him remain in power after the atrocities he has committed against his own citizens.

The use of chemical weapons against his opponents of 2012-13 was an appalling crime against the people of Syria. Barrel bombs, inaccurate and improvised explosive devices are dropped onto civilian areas from aeroplanes and helicopters.

Assad is deliberately pursuing a policy of ethnic cleansing against the Sunni majority, and preventing refugees from returning. The resulting refugee crisis cannot be solved until Assad no longer holds sway and people can return to their homes and families. His shameful policy towards Daesh increases the difficulty of defeating them.

This is a moral imperative for action. Only Assad’s removal offers hope for a peaceable conclusion in Syria, and it is the policy of the British Government to work for his departure.

We are supported by governments in the Middle East. The regional powers of Saudi Arabia and Turkey are strongly against the Assad government, and are insisting he must hand over power as part of a solution to the conflict.

President Erdogan of Turkey has said we cannot “accept a dictator who has led to the deaths of up to 350,000 people”. The Saudi Arabian foreign minister, Abel Al-Jubeir, said on 29 September “there is no future for Assad in Syria”.

It is very clear that Assad has no legitimacy in the eyes of Syria’s neighbouring states.

There is consensus in the West too. The key Security Council nations, the US, UK and France, are all opposed. David Cameron made it clear again last month, that President Assad “can have no part in the future of Syria”.

The French foreign minister said of the Syrian refugees, “how can you imagine that they go back to Syria if we tell them that the future of Syria is Bashar al-Assad?” President Obama has reiterated his stance on Syria as “defeating Isil requires a new leader and an inclusive government that unites the Syrian people”.

Whatever settlement can be reached, it must include Assad stepping down from power.

Seventeen nations convened in Vienna on Saturday to work on beginning a dialogue to resolve the crisis. There is speculation circulating about Russian proposals for an 18-month constitutional reform process, followed by early elections, that makes no mention of Assad stepping down.

The Russians deny such a proposal exists, but even that is indicative of their policy: there is no sign they are prepared to withdraw support from Assad.

Besides the many foreign states, the Syrian National Council, as the main moderate opposition group, is also completely opposed to Assad remaining. Is it realistic to imagine that such a resolution could be generally accepted in the country?

Yet Russia’s military actions are also prolonging the conflict. Airstrikes have been aimed largely at the Syrian opposition forces, rather than the more serious threat of Daesh, with the aim of securing Assad’s position.

Government forces have broken the two-year siege of the Kweris airbase in the north-west, which will allow them to put pressure on opposition-held Aleppo.

President Putin is not looking for a resolution to the conflict, but to prop up an Assad puppet-regime in pursuit of Russian interests, such as its naval base at Tartus on the Mediterranean.

We must persuade Russia to end their support of President Assad in order to secure the future of Syria.

Iran has also been a key supporter of President Assad. They too ought to end their aid to the Syrian government, cease their supply of financial, military and logistical support, and allow the country to decide its own fate.

Our failure so far to work out a solution to the Syrian civil war has given the opportunity for Daesh and other terrorist groups to grow in strength.

Daesh presents a clear threat to Britain, both from the dangers of radicalising young British citizens at home and the possibility of attacks abroad. The bombed Russian flight from the tourist resort at Sheikh el-Sharm in October could easily have occurred on a British one.

In order to defeat Daesh, we must first ensure that Assad is removed from power and a new government established that can include moderate Syrian opposition and the Kurds in the north and east.

We must remember our resolve as Britain enters the Vienna talks. If we are to continue to have effective foreign policy we must make it a priority to back up our words and work with our international partners for the removal of Assad from Syria.