The publisher put itself up for sale earlier this month, as it continues the strategic review it started last year to find a solution to the repayment of £220m in high-yield bonds, which mature in June 2019.

In a statement published late on Friday (19 October) as it announced its increased stake, activist investor Custos, headed by chief executive Christen Ager-Hanssen, said Johnston has “become a textbook case of shareholder-value destruction”.

“When I first announced Custos’ campaign to fight for shareholder rights in the autumn 2017, I said that the board is doing nothing more than rearranging the deck chairs on the Titanic and that their only interest in JP was to protect their ability to continue with milking the company for cash. Regrettably I have now been proven right,” said Ager-Hanssen, who in July had threatened the publisher with legal action if it were to opt for a pre-pack.

Ager-Hanssen accused Johnston’s board of “corporate theft” in his statement and said its bond agreement “cynically deprived shareholders of their fundamental right and power to hold the board properly to account and to change the board as they see fit”.

He called the board “nothing short of a disgrace” and said they “literally have no clue as to how to create shareholder value”.

“They do not understand the concept of monetisation of audience in the digital age. They never had a credible strategy,” he added.

“Custos obviously have no confidence in the board or its advisers but our increased holding prove that we continue to have confidence in the underlying business. Employees, at all levels, have been reaching out to me from within JP, excited by the prospect of change and offering Custos their support.

“They crave new leadership and a proper forward-thinking strategy fit for the digital age.”

In response to Custos’ statement, Johnston Press said: “We launched the formal sale process last week so that interested parties could make offers for the company. That process continues and remains our focus.”

The publisher, which owns i as well as almost 200 regional newspapers, recorded a total statutory revenue of £93m and operating profit of £7.4m in its H1 2018 results while net debt was reported at £140.2m.

Shares in Johnston Press opened at 2.01p today, down 1.47%, but had rallied to 2.63p at the time of writing. The share price had dropped as low as 1.3p last week.