Trade union Unite has called on the UK government to block the sale of Arm to Nvidia over fears it will hamper the country's tech sector.
The organisation also said that employees at the Cambridge-based chip maker had been "fobbed off" about the future of the company.
There is a growing backlash from within the industry over the $40 billion (£31bn) deal, with MPs and industry experts concerned that Nvidia will dismantle Arm's UK operation and move jobs overseas.
Daniel Zeichner, MP for Cambridge, will be attending a virtual Unite meeting this week to listen to the concerns of its members. He will then urge the government to intervene in the deal.
He has previously raised the issue in the House of Commons, questioning: "Why on Earth would we want to throw away such a bargaining chip in advance of trade negotiations?"
His concerns are backed by the shadow business secretary Ed Miliband and Unite's regional officer Matt Whaley, who said the deal is not in the UK's national interest and suggested it could potentially see Arm's UK operations run down.
"It would be madness to put this at risk by allowing Arm to be flogged to a multinational that would benefit from it being dismantled," Whaley said in a statement. "Our members have valid worries about the Nvidia deal, which have not been helped by their being kept in the dark by Arm's leadership and fobbed off with excuses about the sale being 18 months away.
"If ministers truly want the UK to lead in science and technology, they should be protecting tech firms from being hollowed out by detrimental takeovers and providing the investment needed for the sector as a whole to flourish."
A spokesperson for Arm said that communication have been ongoing, with CEO Simon Segars and Nvidia boss Jensen Huang both holding multiple interactive sessions with Arm employees. They said it was also "clearly communicated" that the process does not have a specific timetable and employees will be kept informed.
