Media playback is unsupported on your device Media caption Independent unionist Lady Hermon says the Crown Solicitor's Office gave the advice.

The Crown Solicitor's Office in Belfast advised the government that a no-deal Brexit would breach the Good Friday Agreement, a Northern Ireland MP has claimed.

Independent unionist Lady Hermon also asked the prime minister to publish the advice.

It came as Boris Johnson faced MPs in the Commons ahead of a showdown over Brexit.

But Mr Johnson said he had not seen any such advice.

He also claimed the Irish border backstop would breach the agreement.

The Good Friday Agreement was a peace deal signed in 1998 by the Stormont political parties and brokered by the British and Irish governments, to help end decades of violence known as the Troubles.

During the Brexit negotiations, both the UK and EU pledged to protect the agreement.

Mr Johnson has repeatedly said the Irish border backstop in the Brexit deal - designed to maintain an open border unless and until another solution is found - breaches the deal.

He claimed it was a "simple fact" that the backstop gave Dublin more influence over the affairs of Northern Ireland than the UK.

'Any such advice'

Former Ulster Unionist leader Lord Trimble is also of that view.

However, Lady Hermon claimed in the Commons that legal advice had been sent to the government that in fact a no-deal Brexit would breach the Good Friday agreement.

She also accused Mr Johnson of treating Northern Ireland and the agreement in a "careless manner".

If the UK leaves the EU without a deal on 31 October, the backstop will not take effect.

Both Dublin and London have committed to avoiding a hard border, "including any physical infrastructure or related checks and controls".

Lady Hermon called on the prime minister to publish, in full, any legal advice he had received about how a no-deal Brexit might contravene the agreement.

But Mr Johnson said he had not seen "any such advice".