Voters could be able to cast their ballot with a pen in future after fears that pencils could lead to fraud.
The Electoral Commission received around 200 calls from worried voters about the issue around the time of the EU referendum in June.
Many Twitter users posted online that they were using pens because of fears that their vote could get changed.
The commission said it was looking into "alternatives to providing pencils for voters in polling stations which could improve confidence".
Lib Dem peer Lord Rennard asked the Cabinet Office what assessment they had made of the reported concerns.
Baroness Chisholm of Owlpen replied on behalf of the government:
The government has noted the Electoral Commission's comments on this issue in its report on the EU referendum.
The rules governing the conduct of the referendum, which were based on the legislation in place for UK parliamentary elections, did not specify the type of writing implement that electors must use to complete their ballot paper and voters were able to use the pencil provided or mark their ballot paper with a pen if they preferred.
There were also specific safeguards in place to protect the integrity of the ballot.
"We are not aware of any cases of ballot papers being changed at the referendum," she added.
A report on the EU referendum from the commission, which was published in September, said that the reason that pencils had always been used was due to "practical reasons" - "with ink pens there is always a risk that they may dry out or spill; ink may cause some transfer of the mark the voter has made on the ballot paper when they fold it, potentially leading to their vote being rejected... if it looks like they have voted for more options than they are entitled to."
It added that the commission used Twitter to "reassure electors" that they could use either a pen or a pencil. Happy voting...