Voters are being urged not to use pens when they cross their EU referendum ballot papers as it could cause them to "smudge".
Mid-way through polling day, East Northamptonshire Council tweeted out a warning, despite both ink or graphite being acceptable voting tools in the eyes of the Electoral Commission.
Please use a pencil on your ballot paper as ink can smudge when its folded which could make the paper doubtful & it may not be counted
-- EastNorthantsCouncil (@ENCouncil) June 23, 2016
Concerned voters in Weymouth were told there was "not enough time for votes to be rubbed out", after Weymouth and Portland Borough Council received three calls from people wanting to clarify if they could cast their vote in pencil.
The confusion caused Manchester City Council and Hillingdon Council, west London, to tweet that pens could be used, while Sandwell Council, near Birmingham, told voters they could bring a pen but urged them not to ask staff for one.
It's true - you can use a pen OR pencil on your ballot paper! ? #EUref ^CS
-- Hillingdon Council (@Hillingdon) June 23, 2016
Soon, the hashtags #usepens were circulating on Twitter encouraging pro-Leave voters to come to UK polling stations armed with pens over suspicions that their pencilled-in crosses could be tampered with.
Don't #usepens at the polling booth, as THEY can tip-ex over it.
Instead, take a block of granite, a hammer, & a chisel - make it count.
-- Richard James (@RJSHutton) June 23, 2016
#usepens Brexiters don't forget to wear your tin foil hat to deflect Mi5's mind controlling radio beams.
Resistance is futile!
-- JustSomeGuy (@JohnWibbly) June 23, 2016
-- Alex William Day (@alexwilliamday) June 23, 2016
#usepens but not Bics or Staedlers, these can be remotely controlled from Brussels! Use only Swiss Caran d'Ache for maximum independence!
-- Lewis (@gastrobrite) June 23, 2016
I'll be taking needle, thread and employing a running chain stitch style to mark my vote. I'm taking no chances.... #usepens
-- Martin Allen (@martinallen72) June 23, 2016
Don't #usepens . Ink erasers exist. Use the blood of your first born after its been sacrificed to Neptune, there's no undoing that
-- Mehreen Mahfooz (@mehreenmahfooz) June 23, 2016
In the UK, pencils are traditionally used for marking ballot papers and available inside polling stations for voters to use, a spokesman for the Electoral Commission said.
"However, there is nothing to stop a voter from using a pen to mark their vote - there is no legal requirement for ballot papers to be marked with a pencil," he continued.
Remember - using a pencil to vote in the #EURef is fine. But you can use your own pen if you wish. Just don't leave it behind!
-- Electoral Commission (@ElectoralCommUK) June 23, 2016
"The reason that pencils are traditionally used is partly for historical and practical reasons: with ink pens there is always a risk that they may dry out or spill.
"Also, ink may cause some transfer of the mark the voter has made on the ballot paper when they fold it, thus potentially leading to a rejection as it may look like they have voted for more options than they are entitled to."