Brexit. Why do Brits want Out of the EU?

If such would be done in my state, the state would do it via the Permanent Representation of the State North Rhine-Westphalia to the European Union . If a party, not in our state's government (we've a coalition government, conservative [CDU] and liberals [FDP]) wanted to tell something to other EU-countries, they would use either our state's representation or ... do it as is discussed here.

IGot any examples in Germany or anywhere in the EU ...

Incidentally, I don't know if Northern Ireland has the right-or should have the right-to remain in the EU and also in the UK or not. That's for the Northern Irish, the UK and the EU to thrash out among themselves. I just don't see where a legislator no longer in any governmental executive position gets off telling the heads of other countries what they may do, let alone 27 heads of state.

NGO's do it, so why not leaders of political parties?

The EU has nothing to do how the United Kingdom of Great Britain and Northern Ireland organises the countries of the union.

Didn't imply they did, but if one of the UK countries applies for admission, the EU will have to decide whether to accept or reject the application, or even if the application could be considered legitimate in the first place.

PS: Foster's anti-EU stance is going down in popularity over there. If the majority of people in Northern Ireland want in to the EU, and get joined by a lot of people in Scotland, things could get very interesting as regards the UK union.

She is the head of state no longer, but that letter to 27 heads of foreign nations implies that she intends to be regarded as having the authority she used to have when she actually was in a position of governmental authority.

Foster's letters were nothing more than an attempt by her to send a message that she really is still the First Minister, the vacating of the position was just a technicality.

The letterhead lists the DUP and the symbol of the Northern Ireland Assembly. Since in parliamentary systems the leader of the majority party in the legislature is the head of state, that symbol is ambiguous.

Not at all ambiguous was the text of the letter which instructed EU heads of state how to regard Northern Ireland's EU status, which would only make sense coming from a head of state. The letter was an attempt by Foster to pretend that she still is the de facto First Minister of Ireland.

The British government appears to have bowed to the Republic of Ireland’s demand that Northern Ireland will not diverge from key EU laws and regulations in the future so as to ensure that a hard border does not return to the island.

According to sources, MEPs were told by the chief Brexit negotiator, Michel Barnier, that Theresa May had conceded after days of intense talks that the province would be treated as a special case with “continued regulatory alignment” between the north and south of the island after Brexit.

A draft of the text of a 15-page joint agreement between the European commission and the British government is said to include a commitment in paragraph 48 that “in the absence of agreed solutions the UK will ensure that there continues to be continued regulatory alignment” with the internal market and customs union.

It is understood Ireland sees the phrase “regulatory alignment” as providing the highest degree of comfort to both sides, allowing talks to move to the next phase while at the same time giving room for manouevre for negotiations in the second phase.