Boris Johnson has been accused of planning an “emasculation” of the devolution settlement, with senior officials and politicians warning that plans for a post-Brexit UK-wide internal market will put Scotland and Wales on a collision course with Westminster. As support for Scottish independence shows a sustained polling lead and the Welsh parliament prepares for a debate on Wednesday about holding an independence referendum, the UK government has been accused of bringing a “statutory fist crashing down” as it attempts to regulate policy and standards across the four parts of the UK. Sources voiced concerns about a more aggressive approach towards devolution from a new generation of Conservative politicians. Some observers believe coronavirus has brought home the true extent of the devolved parliaments’ ability to diverge from London. Health is a devolved matter, and the four countries of the UK have reached contrasting decisions and timelines for imposing and easing lockdown measures. The Welsh government in particular has profound concerns about a lack of communication with the UK government. Its first minister, Mark Drakeford, has not spoken to Johnson since 28 May, which was also the last contact Nicola Sturgeon, the Scottish first minister, had with the PM. Drakeford said last week: “If you are minister for the union [the title Johnson used when he became prime minister], speaking to the component parts of the union seems to me a sensible way of discharging those responsibilities.” Immediate concerns surround proposals to legislate for a post-Brexit UK internal market, which are expected to be published before the Commons recess this month and are believed to include two elements that could undermine the powers of devolved parliaments. First is a plan for an unelected oversight body that would hold any new devolved bills to a “market impact test”, which the Scottish government believes would have jeopardised Scotland-only initiatives such as free university tuition, minimum unit pricing for alcohol or the introduction of a smoking ban before the rest of the UK. Second is the proposal for a “mutual recognition regime” requiring regulatory standards in one part of the UK to be automatically accepted in others. Jeremy Miles, the Welsh counsel general and minister for European transition, said this would “drive a coach and horses through the capacity of individual governments in different parts of the UK to deliver policy objectives in their economies”. In practice this could leave them unable to reject UK government decisions on, for example, chlorinated chicken or genetically modified (GM) organisms, he said, adding: “If the UK government does what it tends to do, which is to deregulate, it will create intolerable pressures on the UK in terms of internal market.” A senior member of the Northern Irish assembly suggested that Michael Gove, who this month was appointed by Johnson to head up a cabinet sub-committee on the union alongside Rishi Sunak, is trying to reassert his government’s power over the devolved administrations. Michael Russell, Scotland’s Brexit minister, described “an inbuilt hostility to devolution” and said: “This group don’t believe, in the era of Brexit, that they should be sharing power with anyone. Some of them are senior ministers. They certainly don’t believe that there is any right for the Scottish parliament, or Welsh assembly, to operate.” Sources in all three devolved governments describe varying degrees of frustration at the lack of consultation or clarity, although the Brexit withdrawal agreement’s Northern Ireland protocol means exceptional rules will be in place from January, which Johnson initially tried to dismiss, claiming there would be no checks on goods entering the region. While Miles insisted the Welsh government “want[s] the union to work”, he said any mutual recognition scheme “needs to be agreed between the four governments, not imposed by one, and it needs to be flexible and nimble, not a statutory fist crashing down across the UK.” Proposals to enshrine mutual recognition in law would “create a huge constitutional fight”, he said. “In essence it emasculates the devolution settlement. That’s not going to be tolerated.” The Welsh and Scottish governments have written to Gove setting out these concerns. Russell said his letter made it clear that “we’re not going along with it. If it’s a voluntary code we won’t observe it, if it’s legislation we’ll challenge it every inch of the way”. A UK government spokesperson said: “We continue to seek a shared approach to the UK internal market with the devolved administrations. Unfortunately, however, the Scottish government voluntarily withdrew from this piece of work over a year ago. We will continue to engage with all three devolved administrations on how best we can bring people together and protect businesses throughout the UK.”