A race against time is underway to complete a controversial gas pipeline between Germany and Russia before US sanctions approved this week can be imposed against it.

The world’s largest construction ship, the Pioneering Spirit, is currently laying the final offshore section of the Nord Stream 2 pipeline under the Baltic Sea.

But the Swiss company that owns the vessel could be forced to pull out of the project or face US sanctions within weeks.

Less than 100 miles of the pipeline remains to be laid under the Baltic Sea, and Gazprom, the Russian state energy company, says it will be finished in five weeks.

But in a move that threatens to strain relations between Germany and the US, the House of Representatives this week voted to impose sanctions against any company that takes part in its construction.

That has left Gazprom facing a race to complete the pipeline before the sanctions come into effect.

US lawmakers led by Senator Ted Cruz are forcing the sanctions through Congress after the Trump administration declined to impose any. President Trump says he will sign the law once it is passed.

Senator Cruz and his allies accuse Russia of using Nord Stream 2 to weaken Ukraine’s economy by bypassing existing pipelines to western Europe that cross its territory.