The defence secretary has said China needs to modify its cyber-behaviour and adopt a code of “fair play” if Beijing wants the British government to allow Huawei technology to be used in future 5G mobile networks.

Ben Wallace said a long-awaited decision on Huawei was coming soon, although he could not give a firm date, and told a defence industry audience any conclusions about the company had to be “more than just technical”.

Spelling out an additional precondition, the minister said: “This is also about behaviour. You know, it wasn’t that long ago that the United Kingdom and other nations called out China for some of its cyber-activity publicly.

“If we are going to allow countries access to our market, I think we should all expect a code of behaviour that is fair play – we are British, we believe in fair play. So I think that will also be reflected in those discussions.”

The UK has been grappling with whether to allow Huawei to supply 5G network technology for months, a decision that led to the sacking of Gavin Williamson as defence secretary by then prime minister, Theresa May, for leaking what was intended to be the final decision.

The decision held that Huawei, the market leader in 5G technology, would be allowed to supply “non-core” parts of the network. But after May’s replacement by Boris Johnson, this has come under review, with the US demanding Huawei not be used.

Washington repeatedly said it would have to review its intelligence sharing with the UK if Huawei were adopted in British phone networks, because it fears the Chinese company’s technology could be compromised in the future.

China, however, has warned not using Huawei as a supplier would delay the rollout of 5G in the UK. Liu Xiaoming, the Chinese ambassador to the UK, said Britain would “lag a year-and-a-half behind”, according to some forecasts, and dropping Huawei would “send a bad message to Chinese business”.

Wallace conceded the Brexit crisis had delayed the timing of any announcement. The minister said he could not provide an exact timetable because “obviously there’s been some chop in the government, up and down”.

The defence secretary was speaking at DSEI, Europe’s biggest arms fair, which is attended by an estimated 35,000 delegates. More than 100 people have been arrested for trying to disrupt preparations for the controversial event.

Wallace also said he wanted to beef up drone security at airports, two days before a planned climate protest at Heathrow aimed at disrupting flights in and out of the country’s busiest airport.

Flights were also disrupted last December for several days at Gatwick, amid confused reports of drone sightings that presented a risk to civil aviation.

Wallace said that the RAF would start working on a three-year programme with Italian defence company Leonardo that would be “looking at how to detect, track, identify and defeat rogue drones”.

It is understood Leonardo will also help enhance current anti-drone measures in an attempt to prevent future incidents, although few extra details as to how that would work were available.

Last week, the Ministry of Defence was awarded an additional £2.2bn in the spending review, a real-terms increase of 2.6%. Wallace told delegates that extra spending was necessary because “we do have to break the cycle, the traditional cycle where often our appetite did not match our stomachs”.

The defence secretary said that “led to the annual hollowing out of our capability and plans, which ultimately, let down the men and women of our armed forces”. By 2021, the defence budget will reach £41bn.