For three hours on Monday, a tag-team duo of NDP MLAs attempted to fill in the gaps in the chronology of the mysterious Global Transportation Hub land deal, at a hearing of the provincial Public Accounts Committee.

But they say they're frustrated because government members on the committee are blocking the the most crucial witnesses from testifying.

The NDP is most concerned it hasn't been able to question Laurie Pushor.

Back in 2013, Pushor negotiated the GTH land deal at the request of then-GTH minister Bill Boyd.

In 2013, Laurie Pushor was called on by then-GTH minister Bill Boyd to negotiate the purchase of 204 acres of land. Pushor agreed to a deal that saw the GTH pay Regina developer Anthony Marquart $103,000 an acre for 204 acres of land, which was far more than government appraisals said the land was worth.

Marquart made about $5 million on the deal.

At the time, Pushor was a senior advisor in the Ministry of the Economy. Now he runs the entire ministry, as deputy minister.

"Pushor is still employed by the government and it wouldn't be hard to get him to the committee," NDP MLA Nicole Sarauer said to the committee, which is dominated by Saskatchewan Party members.

"Time and time again the government members of this committee have blocked him from coming," she said.

Sarauer points out that at multiple committee meetings the NDP has requested to have Pushor and former GTH CEOs testify at the committee, to no avail.

Instead, the government members have agreed to allow Nithi Govindasamy, the deputy minister of Highways, and Bryan Richards, the CEO of the GTH, testify.

But the two men have been unable to answer many of the key questions for a variety of reasons.

Many of the controversial events surrounding the GTH land began in early 2012. Richards didn't start at the GTH until August 2013 and Govindasamy wasn't in his current role until September 2013.

Pushor negotiated the GTH land deal but left Richards and his staff, and Govindasamy and his staff, in the dark.

Many of the key decisions were made in late November and December 2013 and both men were on extensive holidays during that time.

The NDP attempted to reverse the January 2017 decision of the committee that effectively blocked any additional witnesses from testifying.

But the Saskatchewan Party members used their majority to vote down that motion six to one.

That decision means Monday's committee meeting is the last one that will consider the GTH land deal.

In a news release, NDP MLA Cathy Sproule was quoted as saying "to have Sask. Party members shut down the discussion entirely shows how desperate they are to keep the facts of this scandal hidden from the public."

Sask. Party MLA Paul Merriman said he was concerned that the NDP was once again trying to get Pushor and others to testify before the committee.

"That's concerning. We've done this twice," said Merriman, referring to the NDP's efforts to call these witnesses. "We could keep going around on this over and over again," said Merriman.

NDP MLA Nicole Sarauer said she's frustrated that the government is blocking key GTH land deal witnesses from testifying. (Saskatchewan Legislature) "My concern is that the auditor has done her investigation and her team has done the investigation as well as the RCMP with the Opposition's request that the RCMP looked into this. The RCMP are currently investigating this as well. I think that we should allow them to do their work."

Sarauer responded that questioning witnesses about government expenditures is the job of the public accounts committee and something the public expects politicians to do.

"Everywhere I go around Saskatchewan this is the question that I get. I get concerns about this GTH land deal," Sarauer said.

And she said for that reason the NDP will keep pushing for answers.