Ulster MP Ian Paisley Jnr was suspended from the House of Commons for 30 days for not registering a luxury family trip to Sri Lanka, which saw him receive £100,000 in hospitality from the Sri Lankan government.
Mr Paisley disclosed perks including business class flights, helicopter trips and regular visits to tourist attractions.
But the Parliamentary Commissioner for Standards found he failed to declare the full £100,000 total, instead estimating the perks to be worth £50,000.
Mr Paisley had already apologised for what he said was his “unintentional failure” to register the hospitality.
The ban was imposed by the House of Commons Standards Committee, which said his actions “were of a nature to bring the House of Commons into disrepute”.
His suspension from the house could trigger a “recall” process that would see his North Antrim seat given the chance to boot him out.
It is expected that he will be suspended until November 22, with the DUP minister facing a ban of 30 “sititng days in the house”.
They are called sitting days because the houses “do not sit every working day of the year.”
It could spark a by-election, if 10 percent of the electorate sign a petition calling for one.
Mr Paisley will not be able to have any input into Theresa May’s Brexit plans until the suspension has been lifted.
The Democratic Unionist Party (DUP) were crucial in helping Mrs May to secure office following the 2017 United Kingdom general election which resulted in a hung parliament.
The DUP, which won ten seats in the election, helped the conservatives secure a majority through an agreed coalition partnership.
One of the key sticking points of Brexit is the customs border between the Republic and Northern Ireland – an issue that Mr Paisley may be stopped from voting on due to the commons restrictions.
And DUP leader Arlene Foster previously warned her party will withdraw its support for Theresa May’s government if it adopts a Brexit deal that sees Northern Ireland treated differently from the rest of the UK.
Mr Paisley is due to address the House today.
The committee’s findings said: “In view of the seriousness of this matter, we recommend that Mr Paisley be suspended from the service of the House for a period of 30 sitting days starting on 4 September 2018.”
On Saturday, the minister backed US president Donald Trump’s Brexit remarks for revealing that “the empress has no clothes”.
Mr Paisley criticised the Prime Minister and her recent white paper on Brexit, which infuriated hardline Brexiteers and saw Mrs May clinging on to power by a handful of votes.
Mr Paisley said the DUP had been loyal to Mrs May but suggested his party colleagues had not decided how to vote on the customs and trade bill.
Express.co.uk has contacted Mr Paisley for further comment.