Boris Johnson joins lobbying for UK chip designer Arm to list in London

Government fears damage of losing out to New York in battle to attract tech floatations

Boris Johnson has joined the lobbying effort to convince the British-based chip designer Arm to float in London, as the government fears the damage of losing out to New York in the battle to attract high-profile tech companies looking to list.

After the collapse of the $66bn sale of the Cambridge-based business to US-based Nvidia earlier this year, Masayoshi Son, the chief executive of Arm's Japanese parent company Softbank, immediately snubbed the UK for a flotation.