General Election 2017: Aston Martin seeks political assurances
Aston Martin - which is due to open a plant in the Vale of Glamorgan - has called for political reassurances for businesses after the general election led to a hung parliament.
Chief executive Andy Palmer said a "rapid and decisive policy direction" was needed to ensure firms could continue to plan ahead.
The car-maker plans to build its DBX model at St Athan by 2020.
The new plant will employ 750 workers. It took two years to secure the deal.
The South and Mid Wales Chambers of Commerce, which represents local firms, has also called for prompt UK government action to create business confidence.
Mr Palmer said a clear policy direction was needed to "ensure that business can continue to invest for the long term growth and ensure the global competitiveness of the British economy".
He added: "Clarity over our relationship with Europe must be established quickly together with the wider reassurance to our key trading partners that Britain remains a dynamic and thriving business environment."
Wales beat off more than 20 other countries to secure the St Athan deal, which was announced early last year.
It is receiving £5.8m in financial support from the Welsh Government.
Liz Maher, president of the South and Mid Wales Chambers of Commerce, said: "Our members have been telling us that the political and wider uncertainty of two long years of elections and referenda, and the potential impacts of Brexit, have added to the challenges that Welsh businesses face on a daily basis.
"The electorate's split decision yesterday adds further uncertainty for the business community already grappling with currency fluctuations, rising costs and an unknown future trading relationship with Europe and the wider world.
"The formation of a workable administration that can give voters and businesses confidence around economic management must be the immediate priority."