UK and EU firms to urge faster Brexit deal
The EU is even loosening support from there own businesses
Hardly "losing support" (I assume that's what you mean). Confidence with regards to the future is a top priority for business, and always has been.
"Urging a faster deal" (yes, I know this is the BBC's wording, not yours) is also a potentially misleading representation of the contents of the letter. What they are calling for is an end to uncertainty, which would be helped by things being agreed on faster. "Urging a faster deal" makes it sound a bit like they're pushing for Brexit to happen faster, or that they are pushing for things to be resolved ASAP no matter the costs, neither of which is the case.
Likewise, the letter doesn't favour either side in the negotiations, and nor does its criticism focus on either side. Britain's unpreparedness for the negotiations is at least as much a drag on the progress of the negotiations as the EU's determination to operate to its proposed schedule.
However, the one thing it does come out in favour of is
a successful new economic partnership between the UK and the EU, based on the principles of barrier-free trade
In other words, not the deal the UK government has been pushing for.
And the one thing it actively labels a "risk" is the prospect of "no deal". And who are the only ones who have made statements indicating that "no deal" could be something they might actually aim for? Theresa May and a handful of Brexit hardliners.