Tory MP Jacob Rees-Mogg will appear at a fundraiser for the DUP next month, but has turned down a request to appear at a similar event for the Northern Ireland branch of the Conservative party.
The News Letter reports the prominent eurosceptic will appear next month at an event organised by North Antrim MP Ian Paisley.
Mr Rees-Mogg has been a high-profile figure during Britain's negotiations to leave the EU, and leads the European Research Group, an influential backbench committee of Conservative party MPs.
In a letter to former deputy chairman Frank Shivers, the North East Somerset MP said his was party was "currently working closely with the DUP in Parliament" and as such he was happy to appear at the event.
Speaking to the newspaper, Mr Shivers said he had approached Mr Rees-Mogg at the Conservative party conference in Birmingham held over a number of days at the end of September into the start of October.
He said he had put the issues to Mr Rees-Mogg and followed it up with a letter.
Mr Shivers said he had also raised the point that it would have been unthinkable for a member of the Conservative party to speak at a Liberal Democrat fundraiser while it was in coalition with them.
A number of Conservative party MPs have previously appeared at DUP fundraisers, drawing considerable controversy.
In September Defence Secretary Gavin Williamson appeared at a DUP gala dinner alongside DUP leader Arlene Foster.
Details of his appearance at the event or his speech were not publicised until after the event, something which it was later claimed was due to security reasons.
A fundraising dinner held in September 2017 by Ian Paisley featured an appearance by Cabinet Minister Michael Gove was investigated by the Electoral Commission.
It related to the circumstances around Mid and East Antrim council purchasing a £1,500 table at the event.
It emerged in September that Causeway Coast and Glens Borough Council also paid £1,500 for a table at the event.
Alan Dunlop, Chairman of the Conservatives in Northern Ireland said: "Back bench MPs are free to speak to anyone they wish to, there is a clear convention within the Conservative Party however, not to speak in support of rival political parties.
"Jacob Rees-Mogg is a highly respected member of the Party with impeccable knowledge of UK constitutional politics and conventions and therefore will be fully aware of this.
"Sadly on occasions, often in an honest defence of their principle political views, politicians find themselves making odd alliances and standing elements of their own political logic on its head. They make themselves look foolish when they do so.
"We will extend understanding to our colleague Jacob on this occasion and hope that when he visits he will accept our invitation for a cup of tea so that we can discuss with him the important political issues facing Northern Ireland in 2019 in detail"