DUP MP Sammy Wilson has defended his call for “guerilla warfare” in opposing the Northern Ireland Protocol saying it has to be destroyed.
He also stood over his comments about Health Minister Robin Swann acting like a "poodle for the unaccountable chief medical officer".
DUP leader Arlene Foster said it was not language she would use and said it may have been better not sent.
Mr Wilson said ministers should challenge the advise they are given.
The East Antrim MP said his party should use “every means we have” to disrupt the protocol which has seen border checks at ports in Belfast and Larne on goods coming into NI from GB.
"We will fight this protocol and the implication of this protocol with every means we have," he told the BBC.
"And if that means we have to use the tactics which Gordon [Lyons Agriculture Minister] used at the weekend, as Arlene as outlines, we will look to see every opportunity there is to attack the protocol to ensure it is destroyed."
The agriculture minister ordered officials to halt action on building checkpoints and other infrastructure on Friday.
It prompted calls for an urgent Executive meeting with Sinn Fein branding the move a "stunt". The matter was expected to be discussed around the Executive on Monday.
DUP Brexit spokesman Wilson originally made his guerilla warfare comments in The Irish Times.
Challenged about the language used, Mr Wilson said it was “metaphorical” and "appropriate"
"It [the protocol] is going to destroy many businesses in Northern Ireland and in the long run destroy democracy.
“It is a political battle we are fighting and we will use every tactic that we can in fighting that political battle.
“In a political context, to use the term guerilla warfare means that when opportunities arise we will make sure we take those opportunities to undermine the protocol and seek to change the government’s mind on implementation."
He added: "The government seems to be focused on getting the trade deal through the European parliament.
“Maybe after April 30 once a trade deal goes through, we will see a different approach. I think it would be nothing short of scandalous if we then rolled over to Europe every time they put pressure on us as a country.”
The NI Protocol was designed to avoid the implementation of a hard border on the island of Ireland by having Northern Ireland continue to follow EU trade rules, thus creating a de-facto border down the Irish Sea.
There have been delays in transporting good across the Irish Sea and some firms have stopped deliveries altogether. Supermarkets have been granted grace periods in order to prevent disruption to food supplies.
However, some retailers have concerns there will be a reduction in supplies once those grace periods end.
Mr Wilson emphasised that the decision by Gordon Lyons to halt checkpoint work was not simply “optics”.
“It is not just symbolism, it is a clear signal to the government that where we can, we will seek to disrupt the protocol.
“We will not lie down under an arrangement that will subvert democracy at the end of the day.”
Mr Wilson was also asked if he wished to withdraw previous comments he had directed online to the Health Minister.
Last Thursday in a tweet, the DUP MP accused Robin Swann of acting like a "poodle for the unaccountable chief medical officer".
Rejecting that this was "escalating the language", the MP said he believed it should be up to a minister to “challenge advice”.
“I believe it should be up to a minister to challenge some of the advice he has been given, especially when it has been proven to be wrong in the past and having damaging effects on other parts of society” said Mr Wilson.
“Everybody has their own way of expressing their views. Sometimes mine are a bit more colourful than others.”
Sinn Fein’s John O’Dowd called it a “complete lack of leadership” by the DUP as a whole.
“I think there is a need for people to use measured language in response to issues which are of concern to sections of our society," he said
"What we are seeing at the moment is a lack of leadership which is raising tension at a time when tension should not be raised."
Meanwhile, the UUP MLA Mike Nesbitt has suggested border checks should be moved to Rosslare so items can be inspected before shipping into continental Europe.
He said: “The EU are adamant that Northern Ireland is enjoying the best of both worlds, with unfettered access to both the UK and EU Single Markets. If that is the case, why not extend that privilege to our friends and neighbours in the Republic?
“I understand the EU wish to protect the integrity of their Single Market, hence the new regulatory regime that amounts to a Border in the Irish Sea. People seem to think the only alternative is a hard land border between the two jurisdictions on this island, but there is a third way.
“This would reinstate the trading relationships that applied for decades within the UK and between the UK and the Republic, arrangements the Government of Ireland and EU were happy with. It also allows the EU to take back control of how goods are tested for compliance with EU regulations, rather than relying on the UK, now a third country, to carry out tests on their behalf."