Business experts clash in Brexit Committee
And on Wednesday morning, there was certainly no there was no shortage of disagreements in the committee corridor.
Chaired by Hilary Benn, the newly-formed Exiting the EU Committee (known in SW1 as the Brexit committee) listened to representatives with business backgrounds.
Their guests were Chair of the TUC, Frances O'Grady, John Longworth, the former Director-General of the British Chambers of Commerce (one of the only major business leaders who backed Brexit), and the Director-General of the CBI, Carolyn Fairbairn.
Mr Benn began proceedings, asking the witnesses what they would like to see in the government's plan for the negotiations to come.
Workers' rights and a Brexit plan?
Ms O'Grady was emphatic that the priority of her organisation is to protect workers' rights in the UK. She said whatever deal is negotiated, "jobs, wages and rights" ought to be at the "heart" of it.
Mr Longworth (who is now Chair of Leave means Leave) said he didn't "want to see a plan" from the government and said from a business perspective, those negotiating should "keep their cards close to their chest".
Ms Fairbairn told the committee that "barrier-free" access to the single market is "what really matters" to small businesses in her organisation in the forthcoming negotiations, but Mr Longworth said the benefits of Brexit can be "crystallised without regard" for the single market.
Mr Longworth argued the government should declare that it is minded to leave the single market and the customs union, so that businesses can plan for 'Brexit day'.
"Leaving the European Union will enable us to formulate trade deals around the world," he added.
Former Cabinet ministers (and Leave supporters) Michael Gove and John Whittingdale raised the prospect of removing what the latter described as the "the burden of regulation". They suggested that the business sector could assist the Brexit process by drawing up a list of unnecessary EU regulations.
Mr Longworth told the Brexit Committee that leaving the EU will bring a "considerable saving" in costs to businesses. He got a chuckle out of some when he referred to a manufacturer of smoked salmon being forced to re-label their packaging because the EU required them to include 'may contain fish'.
But Ms Fairbairn cautioned MPs against focussing on what she called "silly" anecdotal stories about overregulation, as these are of less concern to her members than losing access to European markets.
Labour MP Seema Malhotra asked Frances O'Grady about the impact of Brexit might have on working people.
The chair of the TUC said increased prices will matter to working people since the UK is experiencing the "longest squeeze in pay packets since Queen Victoria was on the throne".
Ms O'Grady warned the committee that removing EU regulations would expose British workers to a "race to the bottom" and risk leaving the UK "the bargain basement" of Europe.
"Whichever way people voted in the referendum, you will be hard pushed to find any working person who voted for worse rights," she said.
The Brexit Committee will continue to hold evidence sessions and hear views from all sides, as part of their inquiry on negotiating objectives of the UK's withdrawal from the EU.
As the detail is thrashed out, this committee will be one to watch.