There is "chaos in the Conservative government", says a document which has been seen by Ireland's leading news organization RTÉ News.
Dublin is especially worried as it is the only country in the EU which has a land border with the EU and there are fears a messy Brexit could unsettle the peace process in Northern Ireland and resurrect terrorist elements within the IRA who want to reunite the island.
The internal report, based on discussions between Irish diplomats and officials in several European capitals, paints a shambolic picture of Theresa May's government's efforts to put together a coherent policy.
Czech Minister 'Felt Sorry' for UK Ambassadors
Czech Deputy Minister for Foreign Affairs Jakub Durr had reportedly told Irish diplomats "he felt sorry for British ambassadors around the EU trying to communicate a coherent message when there is political confusion at home".
At one meeting between Brexit Secretary David Davis and two French ministers Mr. Davis appeared to be avoiding the subject of Brexit, according to the report.
A Czech government minister told Irish diplomats he had found Britain's Foreign Secretary Boris Johnson "unimpressive" but was grateful Johnson had "avoided any gaffes" during a visit in September.
At another meeting in Luxembourg a British judge in the European Court of Justice, Ian Forrester, complained about "the quality of politicians in Westminster."
Judge Forrester said he believed Britain would one day view Brexit as "a great mistake."
UK Government 'Not Thought All This Through'
Last week Irish Prime Minister Leo Varadkar told reporters how unimpressed he was by the UK government on Brexit.
"Sometimes it doesn't seem like they've thought all this through," said Mr. Varadkar.
Irish diplomats in several European capitals say there is a widespread fear that it will be impossible to break the deadlock between the UK and the EU at a key summit next month.
Theresa May's government wants to move the Brexit negotiations on to discuss trade despite having failed to agree on the status of EU citizens in the UK or the cost of the so-called Brexit bill for leaving the EU.
The status of the border between Northern Ireland and the Republic also has not been finalized yet.