The next period of regulated campaigning might have already begun, a partner at the law firm Bates Wells Braithwaite has warned.

Simon Steeden said that if a second election were to be called before the end of the year, the period of regulated campaigning would already have started because it covers the year leading up to a vote.

Last week’s election was called with just two months’ notice, leaving many charities concerned that they could be penalised for activities that took place before they knew an election would happen.

And the failure of the Conservatives to secure an overall majority in the House of Commons means another election could take place before the end of year, said Steeden.

He said the snap general election had demonstrated the unfairness of the lobbying act, which requires all campaigning bodies, including charities, to register if they intend to spend more than £20,000 in the year before an election on campaigning activities that could reasonably be regarded as intending to influence the outcome of the vote.

In an email to charities sent out this morning, Steeden described the lobbying act as “Orwellian”.

He said: “This election has raised further questions as to whether the current rules governing non-party election campaigning are fit for purpose.”

He pointed to the 50 charities that wrote to all of the political parties during the campaign expressing concern about what he described as “retrospective regulation”.

“The hung parliament means that the spectre of another vote will be ever-present, and campaigners will be assumed to be on constant election footing,” he said.

“For example, this could mean that the regulated period for the next election begins today, meaning that campaign groups potentially have to start counting expenditure today.”

He said this would “supercharge” the debate around the lobbying act and would make its reform “an urgent priority”.

“The snap election campaign clearly highlighted the unfair nature of rules regulating non-party election campaigning and their chilling effect on civil society engagement in policy debates during an election campaign,” he said.

In the run-up to the snap election, he said, many charities had relied on the assumption that their previous expenditure could not be “reasonably regarded” as intended to influence the election because they did not know it would happen.

But he warned it might be harder to rely on that assumption if a second election was called, because charities might reasonably be regarded as being “on constant election footing” in preparation for the possibility of an election.