Fear of huge job losses is giving a massive boost to the pro-euro lobby in the Government, according to Sir Ken Jackson, general secretary of the AEEU.
Sir Ken, the union leader closest to Tony Blair, told Personnel Today that Downing Street had been "extremely relaxed" about his recent criticisms of lack of leadership over the euro - be-cause he was making the Prime Minister's argument for him.
Inward investors are "bending my ear week in week out" over the euro, said Sir Ken. Many are threatening withdrawal of investment if Britain does not give a clearer commitment to join.
"I have had conversations with inward investors over the last two weeks and they have told me categorically that Britain must join the euro," he said. "They want to limit costs as far as possible, and exchange rate instability is reducing profits."
The AEEU estimates that 150,000 of its membership of about 750,000 are directly dependent on inward investors. These jobs would go if the parent firm relocated to a country which is part of monetary union.
Sir Ken declined to name which companies are considering withdrawal.
Many inward investors, principally from the Far East, have set up plants in Britain to benefit from the relatively low employment costs and access to the single market. But the usefulness of the single market is limited while the UK stays out of the single currency, adding to transaction costs. The high level of the pound has eroded the value of exports.
New base boosts campaign
The AEEU has set up an office in Dundee to support its recruitment and recognition campaign.
The union, which has pioneered partnership agreements, also announced two further recognition deals. One was at Dundee-based wheelchair manufacturer Lomax Mobility, which employs 140; the other was at assembly firm APW, with 130 staff - where the AEEU has over 70 per cent membership.
AEEU leader Sir Ken Jackson plans to invite business leaders from the Dundee region to meet with union officials. Under statutory union recognition arrangements, due to come into effect in the spring, a union with majority membership in a company or business unit will qualify for automatic recognition.
Consultation papers on the new law were published this month.