Rather than making threats against the unions, the coalition government would do better to actively engage with public sector staff if it wants to avoid mass industrial action this autumn, employment experts have warned.

The recommendations came after business secretary Vince Cable was booed and heckled at the GMB union’s annual conference in Brighton yesterday, following his warning that widespread action over spending cuts could ratchet up pressure on the government to change the law in order to make it harder for workers to strike.

Cable’s comments prompted a furious reaction from union leaders, who accused the government of issuing “veiled threats” to deny people their basic right to strike by tightening what they said was already the developed world’s toughest employment legislation.

Cable attested that the government wanted to have a “mature relationship” with the unions, while warning the “usual suspects” from calling for general strikes in response to budget cuts. He also told delegates that there was currently no “compelling” reason to change existing strike legislation, a move that has been called for by some right-wingers including London mayor, Boris Johnson.

But Cable warned that this situation could change if a wave of industrial action caused “serious damage” to the UK’s economic and social fabric. It was the first explicit acknowledgement by a government minister that the coalition could be inclined to legislate in order to prevent widespread industrial action.

But the Chartered Institute of Personnel and Development urged the government to indulge less in threats and more in improving communication and consultation with public sector workers if it wanted to avoid trouble.

Mike Emmott, the CIPD’s employee relations advisor, said: “Trade unions have the power to disrupt only if employees trust them more than they trust management. The fundamental need is not to ‘manage the trade unions’, it is to manage the employment relationship and communicate the case for change.”

This meant that the coalition government must “strive to avoid heavy-handed action at all costs” as it would mean that any attempts at leading through consensus had failed. Both the government and the unions had heavy duty weapons at their disposal, but neither had much to gain from deploying them, hence Cable only threatening rather than proposing to change the law.

Instead “unions, government, frontline workers and public alike have far more to gain from a strategy focused on building trust and avoiding conflict,” Emmott said.

Andy Cook, chief executive of employee and industrial relations specialist Marshall-James, agreed. “At the centre of this is the battle for hearts and minds of public sector workers. Without their support, the unions cannot go on strike so the key is for government to focus on winning hearts and minds and engage with people, not make threats to change legislation.”