* Senate Republicans have 50 votes to pass U.S. tax bill -Cornyn
* Sterling slips on Irish border worries (Updates prices and market activity to U.S. market open; new byline, changes dateline; previous LONDON)
NEW YORK, Dec 1 (Reuters) - The greenback edged higher against a basket of currencies on Friday on growing optimism that U.S. Senate Republicans would be able to round up enough votes to pass a tax overhaul bill.
The dollar index, which measures the greenback against six rival currencies, was up 0.11 percent at 93.148.
Senate Republicans will grapple on Friday with the possibility of adding a tax increase to sweeping legislation meant to cut taxes on businesses and individuals, aiming to win support from fiscal conservatives worried about the bill's impact on the federal deficit.
The No. 2 Senate Republican John Cornyn said he was confident Republicans have the 50 votes necessary to pass a bill in the chamber.
Republican Senator Steve Daines, one of several senators seen as pivotal to the fate of the tax overhaul, said he would support the bill. Senator Ron Johnson will also back it, according to a Wall Street Journal report.
"I think the markets are pretty excited about that," said Kathy Lien, managing director of FX strategy at BK Asset Management in New York.
Comments by New York Federal Reserve President William Dudley that there is a reasonable case for an interest rate hike in December also supported the dollar, Lien said.
The euro slipped against the dollar, despite data that showed global manufacturing expanded at the fastest pace in years last month and the second-fastest for two decades in the euro zone, driven by robust demand.
The single currency was down 0.33 percent to $1.1863.
"The euro has had generally a good week, and it's almost a dynamic of buy the rumor, sell the fact," said Mazen Issa, senior FX strategist at TD Securities in New York.
"I suspect it's a little bit of profit-taking as we got to the North American session," he said.
The euro is down 0.6 percent for the week, snapping a three-week streak of gains against the dollar.
Sterling slipped from a two-month high against the dollar, getting only a temporary boost from better-than-expected UK manufacturing data, as investors fretted about Britain reaching a deal with the European Union over the Irish border.
The Canadian dollar posted its biggest gain in nearly three months against its U.S. counterpart after stronger-than-expected domestic jobs data fueled expectations for further Bank of Canada interest rate hikes early next year. (Reporting by Saqib Iqbal Ahmed; Editing by Meredith Mazzilli)