The DUP MP was speaking after reports that arch-Brexiteer Boris Johnson had previously given his reluctant blessing to checks on trade between Great Britain and Northern Ireland while he was foreign secretary.
Mr Johnson was guest speaker at last weekend’s DUP conference in Belfast, where he delighted delegates by calling for the backstop to be ditched.
But in a leaked letter to the prime minister, dating from February this year, he appeared to consider checks in the Irish Sea as one solution to the land border problem.
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The report in The Times on Monday also quoted a source close to Mr Johnson who said the “hostile leak” intentionally misrepresented his position.
And East Antrim MP Mr Wilson dismissed it as an attempt to “sow dissent” among those who are united in opposition to Mrs May’s withdrawal agreement.
He told the News Letter: “Don’t underestimate the dirty tricks, the skullduggery, the pressure and the manipulation the government will be engaged in to try and drive wedges, persuade people and weaken arguments as it tries to get this deal through Parliament.
“It is dirty fighting in the trenches stuff now and there is going to be far more of this type of thing.”
The DUP Brexit spokesperson also rejected reports that his party is considering backing a Norway-plus style deal, in which the UK would join the European Economic Area.
He added: “These suggestions that we might be talking to Cabinet ministers about a Norway-plus deal are simply not true, and are deliberately designed to try and cause a rift between the DUP and the ERG (European Research Group), who of course don’t wish to stay in the single market or customs union.
“It is yet another example of the disinformation that people can expect to hear between now and the vote in Parliament on the withdrawal agreement.”
When DUP leader Arlene Foster was yesterday asked about the party’s stance on a Norway-plus deal on BBC Radio 4’s Today programme, she said: “We should look for a better deal ... we are not going to be proscriptive in that better deal.”
Mrs May flew into NI on Tuesday in an attempt to sell her Brexit accord to politicians and the wider public.
During her visit, the News Letter asked the PM why she had allowed the removal of paragraph 50 of the Joint EU-UK report agreed last December, which appeared to rule out an Irish Sea border by handing Stormont a veto.
In her response, she noted that there is currently no functioning Assembly in NI.
But Mr Wilson said paragraph 50 was “not designed as short-term solution”.
He added: “It was intended to give the Assembly the ability for the next 50 years, if the EU were to demand certain regulations be imposed in NI to keep the border open, to make the judgment whether that was going to be detrimental to NI and give us the ability to either accept or refuse to implement it.
“It was not about the situation at present, it was meant to be a long-term safeguard.
“Looking back on it now it is clear she never had any intention of honouring this.”