By Elizabeth Piper
LONDON (Reuters) - Prime Minister Theresa May's attempts to keep her Brexit plans secret provoked a new row on Tuesday when lawmakers criticized her for failing to hand over complete studies on the economic impact of Britain's leaving the European Union.
The government had promised to share more than 50 studies on how Brexit would impact different economic sectors, but late on Monday, it gave them some of the reports with parts redacted because of what it called their sensitivity.
The lawmakers hit back, saying the government was riding roughshod over a democratically elected parliament.
"In my experience ... the best decisions in life are the ones which are held up to the light and tested," Keir Starmer, Brexit policy chief for the opposition Labour Party, told Sky News.
Arguments that the economy would suffer if it left the EU were rejected by many Britons at last year's referendum when the country voted to leave.
But with the economy struggling with lower growth since the vote, some of those who argue that Britain should reverse its decision or at least strive for a softer Brexit that maintains close ties say knowledge of the impact could change minds.
The government has been reluctant to share its impact assessments, with May saying she has to play her cards close to her chest to win the best available deal with the EU.
Earlier this month, parliament used an archaic rule to force the government to hand over what Brexit minister David Davis had earlier referred to as "our 57 studies (that) cover 85 percent of the economy - everything except sectors that are not affected by international trade".
Late on Monday, Davis wrote to a parliamentary committee on Brexit that the papers had been redacted because he had not been given guarantees that lawmakers would keep the details secret.
That move, Labour and the Scottish National Party say, could place the government in contempt of parliament, which could lead to suspension or expulsion from the House of Commons.
"The government is under an obligation to pass this material to the Brexit Select Committee and, if it appears to be failing in the obligation, we intend to raise it with the Speaker," Starmer told the BBC.
"The government could be in contempt of parliament."
(Editing by Stephen Addison)