Nigel Farage has claimed cabinet ministers have been banned from talking to him by Downing Street.
The former Ukip leader also said he wants to be a "bridge" between Donald Trump's US and the UK, the BBC reported.
His comments came after he became the first senior UK politician to meet the president-elect following his surprise victory.
Downing Street did not comment on Mr Farage's latest remarks but previously brushed off the chances of him becoming a go-between, insisting there was "no vacancy".
Mr Farage told BBC Radio 4: "If you wanted to get business from the biggest company in the world and there was someone there that had the contacts and connections, the first thing you do is to employ that person.
"I find the fact that Downing Street don't want to acknowledge me, have banned cabinet ministers from even talking to me, it shows you the sort of very small-minded, petty, tribal level that British politics is at - it's a shame."
Quizzed on his relationship with the president-elect and what he would compare it to, he said: "I can't make big decisions, but I tell you what I can do, what I genuinely can do.
"Is I can help to be a bridge between the government in this country and the new trade department in this country and not just Donald Trump, but his team and his administration.
"And I would like to do that."
On whether he could secure a trade deal for the UK that Prime Minister Theresa May could not, he said he thinks that "trade deal is potentially there on offer".
"He (Donald Trump) is going to be inaugurated in a few weeks time and mark my words this is a very big Anglophile president that is taking over, and that is good for us," he added.
Responding to a question about a spike in hate crime after the EU referendum, Mr Farage said he has received 10 death threats in the last two weeks, but denied he fears for his life.
He added: "Have there been yobs and louts that have behaved badly since Brexit? Yes. But, you know what, they were behaving badly before Brexit. There are always going to be people in our community like that.
"And actually the recent figures show that in the last three months that spike as people saw it hate crime post referendum has now fallen markedly."
Last month, Mr Farage was pictured grinning in a gold-plated lift alongside the president-elect at his New York skyscraper.
Mr Trump then shocked Westminster by sending a late-night tweet saying Mr Farage would do a "great job" as Britain's ambassador to the US.
Britain's International Trade Secretary Liam Fox dismissed Mr Farage's claim ministers were told not to talk to him.
He told BBC's Andrew Marr Show: "I have not had any such instruction.
"We have longstanding understandings of how we deal with incoming administrations in this country. We have got a full diplomatic team that was close to both the Hillary Clinton and the Donald Trump teams preparing for the relationship that we would have to have.
"We don't need anything as an adjunct to what the Government already does, and has successfully done in the past.
"I think we have got a perfectly good ambassador in Washington at the present time. Last time I looked there was no other vacancy."
Liberal Democrat leader Tim Farron said: "Nigel Farage has absolutely no right to speak for Britain on the world stage.
"The vast majority of British people do not share his hateful vision and want to keep our country open, tolerant and united.
"Someone who has spent their career trying to divide our country is not fit to represent it abroad."