The US government owned and then sold shares of General Motors (http://www.usatoday.com/story/money/cars/2013/12/09/government-treasury-gm-general-motors-tarp-bailout-exit-sale/3925515/ ). Did the US government ever vote as a shareholder of GM?
During GM's Chapter 11 reorganization in 2009, a new company was formed, with new stock. The old General Motors Corporation was renamed to "Motors Liquidation Company," and the new company was named "General Motors Company." The new company purchased some of the assets from the old company, and the old company was left to sell off the remaining assets and settle the debts.
None of the stock transferred from the old company to the new one; if you were a GM stockholder of the old company and didn't sell, it is now worthless.
When the new company formed, the stock was not traded publicly. The company was primarily owned by the United States and Canadian governments; together, they owned 72.5%. In 2010, GM had an IPO, and the US government sold most of their stake. By the end of 2013, the US government sold the remaining stake; the government no longer has any ownership in GM.
When we talk about voting rights for stockholders, we are mainly talking about voting for the members of the board of directors. And yes, the government did indeed have a hand in selecting the board of the new company. The Treasury Department selected 10 members of the board, and the Canadian government selected 1 member. There were 19 board members total. (Source)
Unlike some companies, there are not "voting" and "non-voting" classes of GM stock. All the shares sold by the US government are voting shares.