Youth politics Sandtrøen took the initiative to establish a
Workers' Youth League local chapter for students in
Trondheim in 2011, which he also led. He was present at
Utøya during the
2011 Norway attacks, where he hid along the cliffs facing the mainland before swimming away. He resigned in order to take his seat in parliament and was succeeded by Tone Hagen.
Parliament Sandtrøen was first elected as a member of parliament from
Hedmark at the
2017 election and was re-elected in
2021.
2025 Early into his tenure, Sandtrøen was faced with the revelations of many violations of seasonal workers' rights on farms across the country spanning back ten years; which he as a result, called for change in the laws to better protect seasonal workers, further calling it "a paradox that the most vulnerable part of the Norwegian labour force is also the least protected". He and labour minister
Tonje Brenna summoned representatives of the sector in for an extraordinary meeting, aiming to reach an agreement on new measures to tackle the issue. Sandtrøen presented the government's proposal for a law on food waste in April, which would task grocery shops and kiosks to promote products that are about to expire and also reduce the prices of said products. He argued that the law would help the government halv food waste by 2030 if passed. The proposal was put forward to parliament in late May and was passed unanimously. In mid-May, he presented the government's proposal for the agricultural settlement which was set at a cap of 1.1 billion NOK, which was 300 million more than what the state had originally proposed through negotiations with the farmers' associations. At a press conference, Sandtrøen argued that the negotiated settlement would secure agriculture for the future and strengthen national preparedness and self-suffiency. Sandtrøen delivered the government's speech on the state of the nation at the opening of the
Storting on 11 October. The speech details what the government has done in the last year and is traditionally written and given in
Norwegian Nynorsk. ==Personal life==