EU leaders will be braced for a new row next week with the UK Government after it emerged David Davis will refuse to tell them how much Britain is willing to pay towards its Brexit “divorce bill”.

Sparking a fresh clash with Brussels, the Brexit Secretary will not go into any detail on the size of the payment, despite demands from his EU counterpart Michel Barnier for more clarity.

Earlier this week Barnier dismissed Davis’ plea for parallel negotiations over withdrawal terms and a future trade deal ahead of a new round of talks beginning on Monday.

The EU chief negotiator has insisted there needs to be agreement first on the financial settlement, as well as on the Irish border and citizens’ rights before trade deal talks can start.

Davis’ apparent refusal to discuss the bill in detail risks delaying the start of that second phase of negotiations, which are due to kick off in October.

“We are in the season of the Great British Bake Off, aren’t we. So we will make it clear that they have massively overegged their demands,” a source told The Guardian.

“In an ideal world they want to salami-slice us step by step by step,” they added.

“And on you go, up and up, and there is the bill. That is not going to happen and we are not going to play that game.”

Reports earlier this month suggested the UK was willing to cough up £36 billion to settle its obligations, but there has been no official confirmation of that figure. Independent experts have previously estimated the UK exit bill will be around £60bn.

Meanwhile, a report by MPs said the “poisonous tone” of the referendum campaign to leave the EU fuelled the demonisation of immigrants and created huge obstacles to social integration.

The All Party Parliamentary Group (APPG) on Social Integration said migrants should be treated as “Britons-in-waiting” who are expected to eventually gain citizenship instead of being viewed as security threats.

It found newcomers are increasingly leading parallel lives and warned that anti-immigrant rhetoric is making it harder for people to become fully involved in British life.

Chuka Umunna, who chairs the APPG, said: “The demonisation of immigrants, exacerbated by the poisonous tone of the debate during the EU referendum campaign and after, shames us all and is a huge obstacle to creating a socially integrated nation.

“We must act now to safeguard our diverse communities from the peddlers of hatred and division while addressing valid concerns about the impact of immigration on public services, some of which can contribute to local tensions.

“We must start by valuing the contribution of all ethnic and minority communities to the UK. Rather than being seen as security risks, immigrants should be viewed as Britons-in-waiting, keen to participate in their community.”

In the report, the group said it would be “perfectly plausible” for ministers to introduce a regionally-led system for non-EU immigration while “continuing to subscribe to some form of freedom of movement” post-Brexit.

Race hate crimes surged in England and Wales after the EU referendum with police recording a 41 per cent spike in July last year compared to the year before.

Data from 31 police forces showed 1,546 racially or religiously aggravated offences were recorded in the two weeks up to and including the day of the referendum on June 23. But in the fortnight after the poll, the number climbed by almost half to 2,241.

The Home Office report confirmed while 3,886 hate crimes were recorded in July 2015, this jumped to 5,468 in July 2016.