to expect host to let her party guests know that she has a no shoes policy?

If it was a usual party at someone's home, I'd automatically expect shoes off. Many homes are shoes off, so it is normal to count with it.

However, this was "a posh party". How does a posh party look? Were there an official dress code?

https://www.medisupplies.co.uk/Protective-Clothing-Equipment/Overshoes/Disposable-16-Blue-Overshoes?utm_source=google&utm_medium=product_feed_or_listings&pl=STD&ccv=Y&sku=PMC9630&gad_source=1&gclid=EAIaIQobChMIw8zN1N7EhQMVN5lQBh3JwggmEAQYASABEgISKfD_BwE

I do have plastic blue shoe covers for work men - you could offer those to your guests. It will look very fetching with a cocktail 🍸 dress!

I don’t have bunny slippers. I would just go bare footed but my MIL would slippers.

Full PPE?

I live in Scotland and would always expect to take my shoes off in someone's home as I do in my own house. I like to lounge about on the carpet and wouldn't like to think I'm sitting on all the dirt brought into the house by shoes that have walked over god knows what outside!

Body bags! 😂

What do "protective measures" look like at a party? I am imagining plastic sheeting over the floors!

Poor form!

I say that as someone that likes a shoes off house usually, but when we host parties I definitely expect to clean the floors throughly the following morning and let my guests enjoy themselves with or without shoes!

She should have hired a marquee if she is that precious.

I would say you take your shoes off as expected when visiting but for a party people are dressed up and keep your shoes on. I am a shoes off house and so is everyone else and so informal visiting I take off shoes but for a party, I have never seen anyone expecting people to take off the shoes.

How is having to walk around in your socks posh or formal in any way?
I've never been required to take my shoes off at a house party. I've never had any friends with a 'no shoes rule'.
I'd have left.

I know nobody in real life who has a shoes off rule. I also know nobody in real life who has dropped dead from shoe germs.

Mn hivemind is weird, and probably being spurred on by a few foot fetishists posing as neat freaks.

What if you didn’t have tights or socks on? Euuuwwwww, people walking around barefoot? Veruccas! Or if you had on a gorgeous dress and shoes but your toenails were in a bad state? I wouldn’t have been too happy. I don’t go to posh parties but I reckon I’d have had all these thoughts and checked with the host.

We’re a shoes off house, all my friends houses are shoes off too and all DC friends automatically take shoes off at the door here.
But, if I was hosting a posh party I wouldn’t expect everybody to remove their shoes and ruin outfits.

Shoes off is totally alien to me but that’s probably because I’m from the west of Ireland. It’s not something we do here.

Or with a toe-hole having appeared in their tights, as happened to me once. Spending three hours with one's toes curled under isn't exactly conducive to relaxing chat.

Do you wear your slippers when attending house parties then? Cocktail dress and bunny slippers?

This reminds me of the Sex and the City episode where at a "shoes off" party one of the other guests steals Carrie's Manolos.

I don't think a formal fundraising party should be shoes off, no matter what the hosts usual policy is.

YANBU. This kind of thing is why I will always believe it's rude to insist guests take their shoes off. Shoes are part of a person's outfit. And most pavements really aren't smeared in dog shit from end to end. And most people (allergies/low immunity excepted) really aren't going to drop down dead if they encounter - shriek! - a germ.

When I was a kid, we had shoes off in the house UNLESS it was a party, in which case everyone wore shoes! I think it is mega weird to not be allowed to wear shoes at an adult gathering inside a house!

I think you’re being obtuse by acting like you’ve never heard of anyone having a no shoes rule in their home.

I don’t like walking around in bare feet so if I know I’m going to someone’s home then I’ll take a pair of socks in my bag just in case.

If I didn’t take any socks then it would be my own fault because I know that some people have a no shoes rule.

Actually in these circumstances (smart, formal cocktail party or dinner at someone's house where people dress up), it would often be expected to keep shoes on- at least that's my experience of having lived in Hong Kong for 14 years. It would be the exception to the rule.

I don't believe you. Unless you don't know anyone. Full stop.

I'd say about half the houses in our street have a dog, and many of the rest have cats.

Impossible.

That’s super weird, we don’t wear shoes indoors and prefer guests take off but always out as everyone in our family hates wearing shoes (true). BUT if we were having a posh party absolutely NO WAY would I expect shoes off! That’s weird. Especially if the guests were mainly not good friends or family.

If she's styled it as a formal event then it should have been shoes on or a note letting you know hers was a shoes off household.
Culturally everyone I know has a shoes off home so we dress accordingly but if someone new came who didn't know and they wanted to keep theirs on then I'd not mind nor enforce my shoes off rule.