General Motors ambitious viability plan announced a fortnight ago called for up to $16.6 billion in additional aid and the reduction of more than 47,000 jobs across the company’s global resources, but there was another major announcement in the plan that went largely unnoticed. GM also pledged to increase the number of hybrid vehicles it sells from the current eight to 26 by 2014.

Unfortunately for GM, while it may have the technology ready, potential parts shortages, especially for the all-important battery arrays, may end up causing delays. That’s the biggest worry according to GM executive vice president of global powertrain and global quality Tom Stephens. Speaking with Automotive News, Stephens said the original viability pledge for all 26 hybrids was made on the assumption that the components will be available.

It's not just batteries that are in short supply, GM may also have to start producing its own electric motors for its future hybrid and plug-in hybrid vehicles.

One vehicle, the Saturn Vue Two Mode hybrid, already has been delayed because of a component shortage. That vehicle was supposed to have been launched by now but has been pushed back to June, Stephens said.

Tom Stephens is an important man at GM as he will replace the head of global product development, vice chairman Bob Lutz, who is retiring at the end of the year.