Unite, the UK’s largest union, is seeking reassurances from Aston Martin that potential new investment in the brand will be used to secure jobs in the UK.
Indian conglomerate, Mahindra & Mahindra and Italian private equity fund, Investindustrial are both rumoured to be competing investment bidders for the luxury brand. Mahindra & Mahindra is believed to want to buy a 50% stake in the brand for £250m.
Aston Martin has confirmed it is in "advanced" talks with potential investors, but its current owners have ruled out a sale of the business.
Kuwaiti investment house Investment Dar bought Aston Martin for £479m from Ford five years ago.
A spokeswoman for Aston Martin said: "We are in talks for a capital increase. The company was not for sale and our existing shareholders, Investment Dar, are very much committed to Aston Martin."
Unite regional officer, Tim Parker said: “We are seeking detailed information from Aston Martin’s management and the firm’s owners, Investment Dar of Kuwait about the prospect of new investment money.
“We would like any financial investment to be used for the benefit of the UK business to secure both the long-term future of Aston Martin and for our members employed there."
The workforce employs a total of 1,800, including contract and agency workers.