Sanderson says she has no conflict of interest and that the Olympic Park Legacy Company (OPLC), of which she is a Board member, should allow her to vote.
The 1984 javelin gold medallist was told this week by the OPLC's chief executive, Andrew Altman, that she would be excluded from the vote due to a conflict of interest because she has a personal consultancy contract with Newham Council, who are West Ham's partners, and that the contract had not been disclosed.
"I want to be back on there making the decision and I hope it doesn't come to it but I am willing to take legal action if necessary," Sanderson said.
The 54-year-old is the founder and head of the Newham Sports Academy (NSA), which is funded by the Council, but she says she is not a director.
"I have absolutely no conflict of interest," said Sanderson.
"As a local resident and former Olympic gold medallist I believe I am ideally placed to contribute to deciding what is the best long future for the site and I remain objective and open-minded to the two proposals which I believe the Board will receive over the coming days.
"My involvement with Newham has been well-documented in the national and local media over the last four years and clearly is in the public domain, indeed you only have to look at my own entry on the OPLC website to see my ongoing involvement.
"I have been a member of the OPLC Board since its inception and have always been up front and honest about my involvement with the NSA, never knowingly hiding or not disclosing any relevant information or interests, and was recently even asked to provide a written brief on the NSA initiative for the OPLC chairman, Baroness Margaret Ford, for the House of Lords.
"Anyone who knows me knows that I am absolutely committed, passionate and determined to secure a proper and sustainable Olympic Legacy for east London for future generations."
Sanderson said repeated demands for a detailed explanation of her exclusion from the vote had not been answered.
"I have asked the OPLC chief executive to provide me with a full written explanation on his decision and despite my repeated requests this has not been forthcoming," she said.
"Once I have received this I will consider my legal position since my integrity and reputation have been called into question."
The OPLC would not comment in response to Sanderson's demand to be reinstated.
January 2011: Olympic champion excluded from London 2012 Stadium decision