Unions are calling on the government to make sure that BT's telephone network does not fall into the hands of a foreign company.
The unions fear that after BT's shareholders voted to remove a shareholding limit that prevented the company from ever being bought out, the company might be lost to the UK indefinitely.
Communications Workers Union deputy general secretary Jeannie Drake said the government should make sure that a foreign buyout was impossible.
"There are huge security implications in letting the network fall into foreign hands," she said.
Telecoms industry professionals union, Connect, said that ownership of BT's network raised questions of national interest and issues of network integrity.Both unions are asking the government to step in and protect the network, as several groups have announced they are interested in buying parts of the company.
Earth Lease has indicated that it wanted to bid up to £8bn for BT's local loop, while German bank WestLB is thought to be interested in offering some £25bn for the whole network.
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