Upvote for actually quoting facts/references, but I don't think it's necessarily safe to assume the UK will continue to offer reciprocal visa-free access to European Union citizens in the event of a hard Brexit. I mean, it's probably 98% likely but if there's a snap general election before March and we somehow end up with an ultra-euroskeptic prime minister then all bets are off.

Upvoted and accepted for highly relevant quotes, though I agree with @Bob that things could change rapidly over the next few months.

I've added a footnote that in theory, any policy can change at any time. You might book a holiday to country X but political turmoil leads to country X closing the border. Such risks can never be ruled out completely.

@PatriciaShanahan The source is unofficial, one of the many deceptively official-looking sites that have sprung up around electronic travel authorizations. That the site "confirms that travel in both directions between UK and EU/Schengen will remain visa free" should carry very little weight indeed.

@phoog My answer is also backed up with links to the European Parliament and the UK Government website. I have now also added a direct link to the European Commission website rather than only relying on the 3rd party website etiasvisa.com, to verify their quoting is accurate.

I've removed the downvote, but I still do not see any official UK source backing up your claim that "the UK has declared it will not require visas for any EU nationals for short stays"

@phoog True, I only take the EUs word on it. I don't know a UK source on that either, I can only speculate on why we need to get a UK policy statement from the EU rather than from the UK, but I will refrain from such speculation as it will probably turn into a rant against Brexit and the way the UK government is handling it. If it wasn't true, the UK would probably have contradicted this statement by now, assuming the government reads European Commission press releases.

@phoog, The UK has issued a policy paper. In paragraph 13 they state: "EU identity cards would remain valid for travel to the UK initially. Although there would be no immediate change, as we introduce the new UK 4 immigration system from 1 January 2021, we would no longer guarantee that EU citizens will be able to use a national identity card to enter the UK."

The documents focuses more on EU citizens settled in UK (and vice versa), but the quoted paragraph means the entry rules for short stays are not likely to change before 2021.

@Hoki yes, I was a bit overhasty when I read the first sentence ("The UK and EU have agreed a good deal for citizens"). I have deleted my comment.

This answer would benefit from explaining up-front what ETIAS is. Because the first reference to ETIAS is in the first paragraph and is completely unreferenced I ended up clicking the hyperlink and unnecessarily wading through a bunch of text on the European Parliament ThinkTank website to work out what you were on about. There is a description in the third paragraph but I spent 10 minutes of confusion before I got to that point.

Love how the UK guidance document just doesn't even mention the issue of visas. They talk to you about all sorts of details about your passport, but visas? Oh, we'll see that later...

This answer would be a lot better if it provided any sort of legal backing for what it says so confidently - intentions are fine, but they need to be transposed into legislation before they actually take effect, and in the cliff-edge scenario that could well need to happen after the exit takes place, perhaps taking days or weeks. If there's a legal basis for this - for example, if relations would automatically fall back onto pre-EU treaties that are currently in abeyance - then the answer should say as much, but at the moment it's just unsubstantiated aspirations presented without nuance.

@MichaelHomer No such legal backing is currently available.

Well, yes, so perhaps the answer shouldn’t make those claims. It absolutely shouldn’t start out with “certainly”.

@MichaelHomer I have a footnote with the certainly. The linked question also points out that there is no automatic fallback; every country is placed on either Annex I or Annex II.

With no legal backing your footnote is not accurate; there is no “change of policy” involved. In the cliff edge, everyone expects the withdrawal agreement to sort things, and then it doesn’t happen at the last minute and nothing’s been organised. That isn’t a policy change. Answering a question about a “hard, no-agreement Brexit” with an answer presupposing an agreement (which even your sources state as a conditional proposal that hasn’t been agreed) as status quo is not useful and caveating it in the same category as “well, anyone could just close their borders any time” is disingenuous.

If the answer said “It’s likely you’ll be fine (cite your sources here), but plausible in the worst case that you literally can’t legally enter any of the countries for a while”, that would be fair to the question (or whatever the actual, legal fallback position is). As is it’s just hopeful speculation dressed up and I think it’s misleading to the reader.

It's not speculation, it's backed up by statements from both sides.