* After Trump signs bill, Democrats aim for higher relief payments
* Europe launches mass COVID-19 vaccination drive
* OPEC+ meets Jan. 4; Russia supports further output hike in Feb
* POLL-U.S. crude stocks likely fell last week, prods likely rose (New throughout; updates prices, market activity and comments to settlement)
By Laila Kearney
NEW YORK, Dec 28 (Reuters) - Oil prices fell on Monday as concerns about weakening fuel demand and the prospect of higher OPEC+ output outweighed optimism over a U.S. stimulus package.
Oil prices strengthened earlier in the day, with Brent rising above $52 a barrel, as Democrats aimed for larger $2,000 COVID-19 relief payments following U.S. President Donald Trump's signing of a $2.3 trillion stimulus deal. a new variant of the virus in the United Kingdom has led to restrictions on movement being reimposed, hitting near-term demand and weighing on prices, while hospitalizations and infections surged in parts of Europe and Africa.
Brent crude LCOc1 settled at $50.86 a barrel, falling 43 cents, or 0.84%, after trading as high as $52.02 earlier in the session. U.S. West Texas Intermediate (WTI) crude CLc1 settled at $47.62 a barrel, losing 61 cents, or 1.26%.
"We continue to focus on this pandemic and what January is going to bring," said John Kilduff, partner at Again Capital in New York. "The prospects of more lockdowns are looming and I think that is what's holding things back."
A Jan. 4 meeting of the Organization of the Petroleum Exporting Countries and allies including Russia, a group known as OPEC+, also looms over the market.
"While much focus will remain on the demand side of the global oil balances this week and into the new year, the supply side of the equation will be garnering more attention next month after OPEC+ cranks up its production allowances," said Jim Ritterbusch of Ritterbusch and Associates in Houston.
The group is tapering record oil output cuts made this year to support the market.
OPEC+ is set to boost output by 500,000 barrels per day in January and Russia supports another increase of the same amount in February. U.S. crude oil stockpiles were seen declining last week, while refined products inventories likely rose, a preliminary Reuters poll showed on Monday. EIA/S