Boris Johnson suffered his first big rebellion on Tuesday as 36 Conservative MPs voted against the government over Huawei’s involvement in the UK’s telecoms infrastructure, including its next-generation 5G network.

A prominent group of Tory grandees forced a vote on a telecoms infrastructure bill, which would end any role for the Chinese manufacturer after 2022. Although the rebels were unsuccessful in defeating the government in parliament, the “warning shot” vote, as one MP described it, slashed its majority from 80 to 24.

The rebels — including former cabinet ministers Iain Duncan Smith, David Davis and Damian Green and Owen Paterson — believe there are grave national security concerns in allowing the company a role in critical national infrastructure. Huawei denies it could be asked to spy for Beijing.