Is it brexiteer or brexiter?

Dictionary.com defines the suffix -eer:

a noun-forming suffix occurring originally in loanwords from French ( buccaneer; mutineer; pioneer) and productive in the formation of English nouns denoting persons who produce, handle, or are otherwise significantly associated with the referent of the base word ( auctioneer; engineer; mountaineer; pamphleteer); now frequently pejorative ( profiteer; racketeer).

The final note ("now frequently pejorative") may be at play here: new coinages that use -eer in lieu of -er may be an attempt to imply a negative judgment about what is being described. In this case a brexiteer is not merely "one who brexits" but also implies that the coiner of the word considers brexiting to be undesirable.

It is too soon to tell which of the two, Brexiter or Brexiteer will become standard, or whether there will be a British-English//American English divide.

Brexiteer appeared in The Washington Post today, Tuesday, June 28th, page A19 in the column by Eugene Robinson:

Meanwhile, the other leading Brexiteer, U.K. Independence Party leader Nigel Farage, admitted that Britain won't actually see a savings of hundreds of millions of pounds that could be used to improve the National Health Service.

Brexiteer was also used in the Wall Street Journal on June 27.

Ever since the U.K. voted Thursday to leave the European Union, there’s been no end of commentary, favorable and invidious, comparing the Leave campaign to the anti-establishment wave that swept the GOP this spring. In one respect the comparison is apt. Both the Trumpkins and the Brexiteers aimed their fire at a toothless opponent—and the wrong one to boot.

Robinson and the WSJ are at opposite ends of the political spectrum.

My initial scan suggested that Brexiteer was AmE and Brexiter BrE, but not necessarily, as this headline from a Spectator blog shows:

Brexiteers need to act now, or become the most hated people in history

But the Guardian, as of June 21, preferred Brexiter

Paradoxes of a London Brexiter

As did The Times of Israel on June 27.

Lead Brexiter says no need to rush leaving EU

Brexiters and Brexiteers will fight it out over the next few days or weeks, and may the word with the most panache win. That's Brexiteer, IMO. At this point, dictionaries are worthless on the subject. I'm waiting for The Economist.