Risk to human rights after Brexit?

This recent article from the Guardian gave me some cause for thought

https://www.theguardian.com/politics/2019/feb/13/post-brexit-trade-partners-ask-uk-to-lower-human-rights-standards

I'm not entirely sure I believe the excuses from Liam Fox as they seem somewhat to play into the fears from many in the remain camp.  It is possible that there may be a grain of truth in the claims but the reality might be that they weren't entirely significant details in negotiations and those areas may not have been or primary concern.  Blowing the issues out of all proportion might be a good tactic to divert attention away from what seems to be an overall poor performance in terms of negotiating trade deals for a post-Brexit utopia that we seem to have been promised.

Whether human or workers rights are under threat might be a wider issue though.  Consider that some countries, e.g. the US https://en.wikipedia.org/wiki/United_States_labor_law, have somewhat less generous terms of employment that we currently enjoy under the EU and UK rules.  I'm not sure whether a US company may want to have the same employment rules for staff they employ in the UK, certainly benefits such as maternity leave cost companies money, possibly the US approach would be cheaper https://en.wikipedia.org/wiki/Maternity_leave_in_the_United_States 

Or would it be that UK companies themselves would be calling on a relaxation of employment law such that their costs and obligations would be lessened allowing them to be more competitive in the market place.

In the past I have worked for several companies as a consultant and in most if not all of these I specifically signed away the 48hour working time directive limit as part of agreeing to my contract.  I didn't have to do that but in each case it was a simple practical consideration since work for clients may stretch beyond that time limit.

In fact on one assignment in the US a manager actually planned my work such that I was doing almost 7 days straight (and at the very least had to work the weekend) to meet a deadline.  I didn't complain because the company treated employees very well and I certainly had plenty of perks that made up for that, and I was personally happy to help the client concerned.  However, not everyone is so lucky to have a good company and client to work for, sometimes things aren't as happy and cheery and having employment law which means you can stick to the 48hour/week limit or at least have your employer held to some reasonable obligation of duty of care is a nice safety net to fall back on.

Ultimately business is business, it's about making money, and often for larger companies it's focussed on maximising shareholder profits.  There are numerous examples of companies that have prioritised money above other considerations so no matter how much you want to hope that everyone will play nice and fair the only way to ensure that employees, customers, competitors, the environment, are all protected is to have a good strong legal protections and principles in place and certain rights that we stick to.

How much of the above would our current government be prepared to sacrifice to get trade deals, bearing in mind that we are potentially going to be on our own trying to negotiate with very little leverage.