Former EU public servant David O'Sullivan has slammed the UK’s demands to replace the existing Northern Ireland protocol, asking “what is the UK doing?”. The slamming came after Brexit minister Lord Frost proposed plans to Brussels on Tuesday to allow for "significant change" to post-Brexit rules governing trade with Northern Ireland.

       Speaking to LBC host Eddie Mair, Mr O'Sullivan said: “Yeah, I read the speech. And I really think it's incredibly important for your listeners to understand the extent of the exasperation felt in the EU.

       “And in Ireland in particular with Lord Frost’s speech.

       “I mean, this is the man who negotiated the Northern Ireland protocol less than two years ago.

       “It was ratified and signed and ratified by the UK in December of last year.”

       READ MORE: BBC's Adam Fleming breaks down Lord Frost demands to change 'intolerable' Brexit protocol

       He continued: “Now we're suddenly told that this is the worst deal possible.

       “It needs to be completely renegotiated

       “He is apparently proposing a completely new tax which none of us have seen.

       “And, honestly, people are asking, what is the UK doing here?”

       He went on: “I mean, you know, we all understand that there have been some very real practical problems in the implementation of this arrangement

       “And people in Northern Ireland have suffered some inconveniences and some severe disruptions in some cases to the trade, which we need to address in which the commission hopefully is going to come forward with proposals tomorrow to address

       “They may not be sufficient, they may need to be improved.

       “But in the meantime, a UK Cabinet minister basically saying the treaty we signed and ratified some months ago, needs to be torn up and replaced with a completely new treaty is hardly credible.”

       Brexit Minister Lord Frost has proposed plans for an entirely new protocol to replace the existing Northern Ireland Protocol.

       The protocol, the special Brexit deal agreed for Northern Ireland, is put in place to prevent a hard border on the island of Ireland.

       It has been a turbulent month for EU-UK relations over the Brexit protocol.

       Lord Frost believed the new protocol would improve on the current "excessively rigid" protocol and would allow the EU and UK to "get back to normal" by removing "the poison" from their relationship.