The battle over whether LightSquared’s proposed 4G broadband communications network will be allowed to move forward took a turn last week when the company accused a government advisor for putting his company’s interests ahead of his position on the federal advisory board.

Bradford Parkinson serves on the Space-Based Positioning, Navigation and Timing Advisory Board, but he is also the director of Trimble, a Stanford professor and is considered a GPS expert. Parkinson has a multimillion dollar stake in Trimble, which has been leading the opposition to LightSquared’s proposed plan, it has been reported.

LightSquared pointed out Thursday that Parkinson cannot offer an independent view given his ties to a company that has been opposed to the proposed network. Trimble has led a public relations and lobbying campaign against LightSquared.

LightSquared’s concerns also extended to details around Trimble selling $20 million worth of stock in January after the FCC granted its waiver to LightSquared, according to SEC filings compiled by LightSquared.

In regard to Parkinson’s position on the federal advisory board, he denies wielding undue influence on the LightSquared issue.

Read more from Politico about the allegations.

Read more from Politico about the stock sales.