Mark Harper is a former Chief Whip, and MP for the Forest of Dean.

The Commons has had two opportunities to consider the Cabinet’s Withdrawal Agreement and Political Declaration.  On both occasions, the proposals were rejected by significant margins and, each time, I felt that it was necessary to vote against the proposals and my Party’s leadership, for the first time in my 14 years in Parliament. I took these difficult decisions for three reasons.

First, because I was concerned about the risk to the integrity of the United Kingdom from the Northern Ireland backstop.  Second, because of the risk of being trapped indefinitely in a customs union.  Third, because of being left in a weak negotiating position for our future relationship.

It is now clear from the events of the last few weeks in Parliament that there are many MPs who wish to frustrate the decision made by the British people in the EU referendum, and are prepared to stop at nothing to do so. The Cabinet’s Withdrawal Agreement and Political Declaration remain a bad set of proposals. The passage of time hasn’t changed this.

However, I am prepared to compromise to ensure that we deliver Brexit.  If the Northern Ireland backstop came into force, I have concerns, as do many other colleagues – including our allies in the DUP – about the risk of Northern Ireland being left behind in the EU Customs Union if Great Britain pursued regulatory divergence.

The Prime Minister herself has promised that the Government “will make unilateral commitments to Northern Ireland” to ensure “no regulatory divergence” in the future. I want to see this promise given the force of law through the Withdrawal and Implementation Bill, so as to reduce the risk to the integrity of the UK. I have discussed this matter personally with the Prime Minister, and I am hopeful that the Government will deliver.

For me, the Union between Great Britain and Northern Ireland comes first – I want to see the whole of the United Kingdom leave the European Union together. This legal change would help reassure me that this will be the case.

One of the arguments that the Government has made about the risk of the backstop coming into force is that we could avoid it by implementing ‘alternative arrangements’. This was supported by the Commons on 29th January when it voted – by a majority of 16 – to require “the Northern Ireland backstop to be replaced with alternative arrangements to avoid a hard border”.  Unfortunately, the Prime Minister did not secure the required change to the Withdrawal Agreement, and our EU neighbours said they were not persuaded that a hard border could be avoided without the backstop.

However, because we were heading towards leaving on March 29th without a deal, both the EU and the Republic of Ireland had to set out how they would manage the border in a way that would protect their Single Market but avoid any infrastructure on the border itself. Michel Barnier made it clear that in the case of no deal “there will be no hard border”. This confirms that it should be perfectly possible to avoid the backstop coming into force with some goodwill on both sides. For me, both these factors go some way to reduce the risk to the integrity of our country.

The events of the last few weeks in Parliament, both the votes that have been taken but also the Government’s response to them, strongly suggest that if the Cabinet’s Withdrawal Agreement is not approved, then there is a very significant risk that Brexit will not be delivered at all.

That would be a fundamental breach of the commitment given to the British people that we would honour the decision they took in the EU referendum to leave the European Union. It would cause real damage to British democracy. I am not prepared to stand by and see this happen.

It is no secret that the Conservative Party, just like the country, has disagreements about the European Union and our place within it.  The votes that took place in Parliament this week also suggest that although I would be prepared to leave the European Union without a Withdrawal Agreement, and indeed voted to do so if necessary, many of my colleagues are not. As a result, I have real concerns about our ability as a Party to remain united and govern our country effectively if we tried.

What’s more, there is a real risk that Parliament will decide to force the Government to implement a policy such as joining the Customs Union, which would be a breach of the commitments we made in our manifesto, and would also be opposed by the overwhelming majority of the Conservative Parliamentary Party as well as the Party in the country. This would not end well.

For our democratic system to function properly, and for the voters to be presented with a proper choice at a general election, there needs to be an effective, mainstream, centre-right political party. That party is, and must remain, the Conservative Party.  This is particularly important when the alternative to a Conservative Government is one led by Jeremy Corbyn and his supporters. Such a government would present a real risk both to our economic and our national security.

Therefore, in order to ensure the UK actually leaves the European Union, the Conservative Party remains united and able to govern effectively in the national interest, I have concluded that, despite its faults, I will vote for the Cabinet’s Withdrawal Agreement when it is next presented to the Commons.