Postal workers at Royal Mail are poised to stage a fresh wave of strikes after Easter as talks stalled, amid a “scandalous” threat by bosses to put the company into administration. The Communication Workers Union (CWU), which represents about 115,000 postal workers, is close to agreeing multiple strike dates to take place later in April, the Guardian understands, in the long-running dispute between the company and union. A formal announcement of the strike dates is expected this week. Relations between Royal Mail executives and its workforce have been strained during the months-long dispute over pay and working practices. The situation escalated last night when the Guardian revealed the company’s board has threatened to put the loss-making postal service – the regulated UK entity that delivers to every address in the country – into a form of government-handled administration if a deal could not be agreed. The politically explosive move to declare the postal service insolvent is regarded by the board as a last resort and would probably lead to job losses among the 140,000-strong workforce. Darren Jones MP, the chair of the business, energy and industrial strategy select committee, said: “It would be a scandalous outcome of the privatisation of Royal Mail for the shareholders to keep the international, hugely profitable parcels business they spun out of Royal Mail – alongside the significant pay, bonuses and dividends of the past years – while handing back the letters business to the taxpayer to clear up their mess. “If Royal Mail does go into insolvency the government will have to take it over. My committee will have oversight of that process in the normal way.” Royal Mail has also threatened to separate its domestic and international businesses if “significant operational change” cannot be agreed with the unions. The company said it was on track to make operating losses of £350m-£400m this year, even before a ransomware attack that crippled its deliveries from the UK to other countries. It has refused to pay the $80m (£67m) ransom sought by hackers linked to Russia. A spokesperson for the CWU said: “The company as a whole now have a decision to make – do they reach an agreement with the union or do they continue their relentless and daily assault on postal workers in workplaces across the UK? There is no positive future for Royal Mail without the support of the workforce.” A Royal Mail spokesperson said: “We have been clear throughout the dispute that significant transformation of our network and working practices is essential for the business to survive. It is not sustainable for the business to be losing more than £1m a day. Change cannot continue to be delayed. “If CWU persists with further strike action, this would only serve to threaten the job security of our postmen and women and make our pay offer unaffordable.” The union tussle has proved bruising for the Royal Mail chief executive, Simon Thompson, who was accused of “incompetence or cluelessness” by MPs who called on the regulator, Ofcom, to investigate whether the company had broken legal service requirements.