Prime Minister Stephen Harper will make a cameo appearance on an international stage Tuesday night — though it's hardly one he would have chosen.

The prime minister will be cast in the villain's role in an anti-Keystone XL pipeline ad airing during the U.S. broadcast of President Barack Obama's state of the union address.

The ad is designed to build pressure from elements of Obama's political base who want him to reject the pipeline, and it will be broadcast to the mostly left-leaning audience of the MSNBC network before and after the president's speech.

Harper's image appears at the beginning and the end of the ad. It shows him shaking hands with the ex-premier of China, Wen Jiabao.

'Sucker-punch to America's heartland'

The message of the spot is that the proposed pipeline would benefit Chinese companies heavily invested in the oilsands far more than it would help ordinary American consumers.

"It's a sucker-punch to America's heartland," says the narrator, while the Chinese and Canadian leaders are seen pressing palms.

"(The Chinese are) counting on the U.S. to approve TransCanada's pipeline to ship oil through America's heartland and out to foreign countries like theirs. ...Keystone's a sucker's deal for America. Just say no to Keystone."

The ad is being paid for by NextGen Climate Group, led by the deep-pocketed Obama donor and bitter oilsands foe Tom Steyer.

It airs amid anticipation that a crucial State Department review of the project could be released within days, with a final decision coming from Obama sometime after.

There's been no signal from the White House that the pipeline will come up in the president's speech. His friends and foes, however, will raise it Tuesday.

While he's being squeezed by his friends on the left, his opponents on the right have consistently used Keystone to bash him.

It would be surprising if the Republicans didn't refer to Keystone in their reply to the speech, given that they raise the issue at virtually every discussion on economic issues as the illustration par excellence of the president's job-killing, big-government regulatory zealousness.

Republicans keen on project

The Republicans mentioned Keystone in their weekly address looking ahead to the state of the union speech.

"The president's own State Department acknowledged that the Keystone XL pipeline — as just one example — would create tens of thousands of jobs at no cost to taxpayers," said Sen. Roy Blunt of Missouri.

"Now, this project has been stalled for more than five years. It's time for President Obama to approve truly shovel-ready projects like Keystone to encourage private-sector job creation."

The president and his advisers have repeatedly telegraphed that income inequality is their chosen issue for 2014 — a year of midterm elections that will determine whether Democrats exercise any control of Congress for the rest of Obama's presidency.

They point to studies suggesting that economic growth, once shared more equally, now creates spectacular gains for some and crumbs or even losses for the rest.

Obama to make 2014 'Year of Action'

There are also polls suggesting the theme might have some political resonance with swing voters.

Obama appears poised to push for a minimum-wage increase, and preschool for all four-year-olds as part of his broader program. And if Congress doesn't make it happen, he plans to use the power of the presidency to ram that agenda through.

He has told his cabinet that 2014 will be a "year of action" — this is after what's widely seen as a wasted year, marked by a succession of scandals, nosediving popularity, and a rocky launch of the Obamacare insurance exchanges.

And he's made it clear he's willing to unleash a barrage of executive orders to make it happen.

House Speaker John Boehner decried the president's approach, especially after the Republican caucus had begun recently signalling a greater willingness to actually work with the administration.

The top Republican in the Senate, Mitch McConnell, offered two ideas to kick-start the economy this week.

"He could approve the Keystone pipeline," the Kentucky senator told Fox News Sunday. "He could work with us on trade agreements. My party is much more interested in global trade than the Democrats are.

"If he would convince his own members, we can do some business on trade. And he ought to stop things like the war on coal in my state, which have cost us 5,000 jobs during his administration."