Burberry chiefs have told MPs it is not commercially viable to keep its south Wales factory open.
A series of protests have already been held over the closure
Production from the plant in Treorchy, Rhondda will be switched overseas when the site closes at the end of March, the firm has confirmed.
Around 300 jobs will be lost when it closes but Burberry said production costs will be cheaper abroad.
Directors told a committee of MPs the decision followed a-year-long review of its operations.
Chairman John Pearce told the Welsh Affairs Select Committee that the production of polo shirts will be moved to abroad and said some products could be made at greater quality and with "significantly lower" costs abroad.
He said that while 25% of Burberry's polo shirts are made in Treorchy, less than 10% of sales are in the UK.
The firm said it was investing in its factories in Rotherham and Castleford, which make trench coats, but for goods such as polo shirts, cost was more important than place of manufacture, the MPs heard.
More than 300 people will lose their job when the plant closes
In a paper submitted to the committee, Burberry said Wales was "challenging" to compete against the economies of Asia and Eastern and Southern Europe because of its labour intensive low value-added manufacturing industries.
The number of jobs in the Welsh textile manufacturing industry had fallen from 13,000 to fewer than 4,000 since 1991.
"This economic restructuring will understandably prove to be uncomfortable for those who find their jobs caught up in this global shift," said the paper.
Chief financial officer Stacey Cartwright told the MPs that 124 of the original 309 employees at Treorchy had found other jobs and the company was trying to help the rest find alternative employment.
She said more than 200 vacancies had been identified in the local area and 600 more were in the pipeline in call centres and supermarkets.
The GMB union, which has led a high-profile campaign to save the plant, told MPs there would be little work left in the clothing and textile industry in south Wales after Burberry moved out.
The union said it was "deeply concerned" about the levels of pay and hours worked by staff abroad.
Protests have taken place in six cities across the world as part of a campaign to stop the closure.
Co-ordinated protests against closure were held in London, Paris, New York, Chicago, Strasbourg and Las Vegas earlier in February.
A number of celebrities have added their support to the workers campaign including singer Sir Tom Jones, Manchester United manager Sir Alex Ferguson, actors Michael Sheen, Ioan Gruffudd, Rhys Ifans and Emma Thompson, opera star Bryn Terfel, singer/presenter Charlotte Church and comedian and author Ben Elton.