He made the offer, which he insisted would not be delivered on while he was under pressure from protesters, after exiled opposition politician Sviatlana Tsikhanouskaya said she was willing to lead the country.

In a sign of Lukashenko’s growing vulnerability, he faced heckling and chants of “step down” during a speech to workers at one of the large state-run industrial plants that are the pride of his Soviet-style economic model and core support base.

Russia has told Lukashenko it is ready to provide military help to Belarus in the event of an external threat. Lukashenko faces the threat of European Union sanctions after a bloody crackdown on protests following what demonstrators say was his rigged re-election victory last week. He denies losing, citing official results that gave him just over 80% of the vote.

Lukashenko told workers there would be no new presidential election, something the opposition wants, until he was killed.

He also offered to change the constitution, an apparent concession that seems unlikely to satisfy protesters.

“We’ll put the changes to a referendum, and I’ll hand over my constitutional powers. But not under pressure or because of the street,” Lukashenko said, in remarks quoted by the official Belta news agency.

“Yes, I’m not a saint. You know my harsh side. I’m not eternal. But if you drag down the first president you’ll drag down neighbouring countries and all the rest.”

Speaking in a video address from Lithuania, opposition politician Tsikhanouskaya urged security and law enforcement officers to switch sides, saying they would be forgiven if they did so now.

“I am ready to take responsibility and act as a national leader during this period,” Tsikhanouskaya said.

She called for the creation of a legal mechanism to ensure that a new fair presidential election could be held.

Her video was released as Interfax reported that employees from the state broadcaster BT has gone on strike, after several presenters and staff publicly resigned last week in solidarity with the protesters.

The broadcaster was showing re-runs on Monday morning before issuing a fresh news bulletin. Videos on social media suggested BT had at one point aired footage of an empty studio with white sofas, and music playing.

Reuters could not independently confirm that and the broadcaster could not immediately be reached for comment.

Thousands of protesters marched in Minsk to a factory where Lukashenko flew by helicopter to speak to striking workers.

He got a rough reception.

“Thanks, I’ve said everything. You can (continue to) shout ‘step down,'” he said, after struggling to be heard above demands that he be quit.

He then walked away as the crowd chanted “Step down”.

The media outlet Tut.By reported that workers at Belaruskali, one of the world’s largest potash producers, had also threatened to stop production. The state-owned firm, which is a key source of dollar revenue for Belarus, said its plant was still working.

Tsikhanouskaya is a former English teacher who has become one of the leading opposition figures.

She fled abroad last week, saying it was for the safety of her children, but quickly began releasing videos calling for anti-government protests to continue.

The unrest has spread to those normally seen as loyal to the president, as workers from large state factories staged walkouts and some police, journalists from state media, and an ambassador also came out.

The Kremlin said on Sunday that President Vladimir Putin had told Lukashenko Moscow was ready to assist Belarus in accordance with a collective military pact if necessary and that external pressure was being applied to the country.

European Union leaders will send a message of solidarity to Belarusian protesters during an emergency video conference on Wednesday, and Britain joined a chorus of Western condemnation.

“The world has watched with horror at the violence used by the Belarusian authorities to suppress the peaceful protests that followed this fraudulent Presidential election,” Foreign Secretary Dominic Raab said.

(Reporting by Andrei Makhovsky, Maxim Rodionov and Tom Balmforth in Moscow and Kate Holton in London; writing by Matthias Williams Editing by Andrew Osborn and Giles Elgood)