Writing for PoliticsHome, the Tory peer said his decision to quit had been prompted by an opinion poll published last week in which vast swathes of voters described the country as divided – with almost three-quarters saying the divisions splits had grown since the 2016 EU referendum.
“I have been in politics a long time and realise the limitations of building a case on a single opinion poll, but these findings struck a chord with my own experiences,” he said.
“There is an aggressiveness, intolerance and incivility which has emerged in our public discourse which is doing our country immense long-term harm.
“Brexit has become for us a kind of toxic court room divorce battle in which the hatred of the parents for each other, and their refusal to concede ground to the other, has all but obscured their shared love and responsibility for their children.
“It is time to seek selfless solutions that put the happiness and wellbeing of all the people first.”
Urging his fellow politicians to “rediscover the common ground between us”, the Conservative peer said his decision to quit the Government and “step out on a walk” would allow him to focus on “rebuilding that unity of purpose at home and close friendships abroad” that had been lacking in the bitter Brexit debate.