In public, Vodafone and Verizon Communications like to laud each other’s contributions to Verizon Wireless, their US mobile phone joint venture.

Sir John Bond, Vodafone’s chairman, last month spoke of the “good relationship” the UK mobile phone operator has with Verizon. Denny Strigl, Verizon Communications’ chief operating officer, described Vodafone earlier this year as a “very good partner”.