The Republican majority in the US Senate got narrower with the entry of two new Democratic senators, a situation that may further complicate enacting President Donald Trump’s legislative agenda in 2018.

The Senate opened a new working session on Wednesday with the swearing in of Doug Jones, the Democrat who in December defeated controversial Republican candidate Roy Moore in a special election in Alabama and Tina Smith, who temporarily replaces Democrat Al Franken of Minnesota after he resigned on Tuesday following accusations of sexual misconduct, reports Efe news.

Their arrival reduces the Republican majority in the upper house by one seat to 51, the other 49 seats being held by Democrats, 11 months before the mid-term elections in November.

All 435 seats in the House of Representatives will be up for grabs, along with a third of the 100 Senate seats, in the upcoming election and the Democratic opposition hopes to be able to retake control of both houses, although the Republicans currently hold a 24-seat majority in the House.

Jones, who became the first Democrat to be elected to the Senate from Alabama in more than a quarter-century, took the oath of office accompanied by Joe Biden, who served for more than three decades in the Senate before becoming Vice President from 2009-2017.

The 63-year-old Jones will serve until 2024 after defeating Moore, a former judge who was accused by several women of having sexually abused them when they were minors during the 1970s.

Smith, a former lieutenant governor of Minnesota was appointed to the Senate seat on an interim basis when Franken announced his resignation a month ago after being accused by up to eight women of sexual misconduct.

She will hold the seat until November when her state will hold a special election to find a permanent replacement for Franken.

Smith is expected to run in that contest, but she may face other Democratic challengers and the Republicans may try to win that seat, given that Trump lost the state in 2016 by just 2 percentage points.

Vice President Mike Pence presided at the brief inauguration ceremony for Jones and Smith, which was also attended by former Democratic Vice President Walter Mondale, who served under Jimmy Carter from 1977-1981.