Ukrainians have been 'very let down' by the Government's decision to relax sanctions on Russian crude oil, the Foreign Affairs Committee chairwoman said today.The import of jet fuel and diesel refined in third countries will now be allowed amid surging costs – and a trade licence, which came into effect today, permits this 'indefinitely'.According to the licence, the sanctions carve-out will be periodically reviewed as fuel prices rise due to the closure of the Strait of Hormuz and the ongoing crisis in the Middle East.The Government had previously announced the UK would block Russian oil refined in other countries in a bid to 'further restrict the flow of funds to the Kremlin'.Dame Emily Thornberry from the Foreign Affairs Committee said the people of Ukraine 'feel very let down' by the Government's decision to relax sanctions.She told BBC Radio 4's Today programme: 'We are talking about our allies in Ukraine who have been fighting a war bravely against Russia for years and years with our support.'They have looked to Britain as one of their most important allies, and they don't understand, given that we promised that we would stop this loophole in October, and we still haven't done it. In fact, it seems to have got worse. People feel very let down.'She said that Ukraine has been able to attack oil refining facilities, adding: 'The capacity in Russia has gone down by 10 per cent.'It is really hurting the Russian economy and they believe that every bit of joint pressure they make with their allies is pushing Russia ever closer to ending the war because this is absolutely crippling their economy.'Rising fuel costs have rippled through the global economy, with jet fuel prices surging in recent months and squeezing airlines, for which fuel can account for up to a quarter of operating expenses.