naysayer in British English

(ˈneɪˌseɪə )

Substantiv

someone who opposes something or says no to it

He ignored naysayers in his party and decided to run for election.

(...)

Will we see a classic to defy the naysayers?

 The Guardian (2015)

But she should not be swayed by the naysayers on pay ratios and binding votes.

The Guardian (2016)

They asked me to go and find more naysayers.

The Guardian (2018)

But he has taken on establishment naysayers nonetheless.

The Guardian (2018)

The premier advised his audience to ignore the naysayers and stay the course.

The Guardian (2018)

If he does that, he can prove his naysayers wrong.

Times, Sunday Times (2015)

Afren proved naysayers wrong, met annual production targets and saw in the new year with a bang.

Times, Sunday Times (2012)

The naysayers would be wrong.

Times, Sunday Times (2016)

But, these naysayers would argue, it is always just a whiff.

Times, Sunday Times (2012)

Despite the site's phenomenal profile, naysayers still argue that it is yet to prove it can make money.

Times, Sunday Times (2012)

https://www.collinsdictionary.com/de/worterbu...

naysayer 

​noun countable, usually plural

UK: /ˈneɪˌseɪə(r)/

someone who always thinks of reasons to oppose new ideas or solutions to problems

https://www.macmillandictionary.com/dictionar...

https://www.google.com/search?q=site%3Aguardi...

Ich sehe keinen Anhaltspunkt, dass es in BE weniger "naysayers" als in AE gäbe.

FWIW, ebenfalls aus dem Collins-Link in #4 :

 ... naysayer in British English

(ˈneɪˌseɪə IPA Pronunciation Guide )

Substantiv

someone who opposes something or says no to it

He ignored naysayers in his party and decided to run for election.

 ... naysayer in American English

(ˈneɪˌseɪər )

Substantiv

one who opposes, refuses, or denies, esp. habitually ...  

.. naysayer in American English

(ˈneiˌseiər)

Substantiv

a person who habitually expresses negative or pessimistic views

Despite a general feeling that things were going well, a few naysayers tried to cast gloom ... 

https://www.merriam-webster.com/dictionary/yea

https://www.merriam-webster.com/dictionary/nay

https://www.merriam-webster.com/dictionary/aye

https://www.lexico.com/definition/yea

https://www.lexico.com/definition/nay

https://www.lexico.com/definition/aye

So wird auch im BE eine Neinstimme bei einer Abstimmung als "no", im AE aber als "nay" bezeichnet.

As a correction from an actual AE NES: While it may be true that some bodies use "nay" to express a negative vote (I believe that is what is used in the US Congress) – and "aye" and "yea" are also sometimes used to express a positive vote – none of these are by far universal when expressing votes in the US. It depends on the tradition of the body.

Both M-W and Lexico contain entries for "aye," "yea," and "nay" (see links above) and indicate that they are old-fashioned or archaic. Both also contain example sentences where they are used in the context of voting.