Npower chief executive Volker Beckers told the BBC the impact on domestic fuel bills was unclear.

BBC: Energy bill to boost cleaner energy production

The ad features Fabien Beckers of Morpheus Medical, a foreign-born, U.S.-educated business owner who is trying to stay in America.

FORBES: A Common Cause for Both Parties

Coalitions of entrepreneurs are mobilizing to show their support, including Engine Advocacy, a startup and technology advocacy group in San Francisco that counts Mr. Beckers as a member.

WSJ: A New Push for Entrepreneur Visas

Mr. Beckers, a 39-year-old physicist from France, graduated from Stanford University with a master's of business degree in 2011 and set out to build software that could decipher heart defects from MRI readings.

WSJ: A New Push for Entrepreneur Visas