Keir Starmer is planning a trip to Ukraine in the late autumn as he moves to cement his relations with the Kyiv government as it continues its fight against Russia. The Labour leader approached the government of Volodymyr Zelenskiy this summer about the possibility of a visit as opposition leader, with the Labour party writing a letter seen by the Guardian. It affirms Starmer’s support for Ukraine in its struggle against Russia and proposes he travels to Kyiv and holds talks with Zelenskiy. The proposed trip follows a previous visit by Starmer to the Polish border, and visiting British troops in Estonia to affirm Labour’s “unshakeable” commitment to Nato. The letter sets out Starmer’s previous meetings with prominent international figures. Sources in the Ukrainian government suggest a date for Starmer’s trip has not yet been agreed, despite what one said was a shortage in August of high-profile foreign guests. They expressed some reservations about not wanting to antagonise the Conservative party after having received strong support from Boris Johnson and his likely successor, Liz Truss. However, it is understood the principle of the trip has been agreed and organisational planning is under way, with Starmer looking likely to undertake the journey later this year. Johnson is an enormously popular figure in Ukraine, after the delivery by the UK of anti-tank weapons ahead of Vladimir Putin’s invasion. He travelled to Kyiv for a third time on Wednesday for Ukraine’s independence day, having first visited in April soon after Russian troops abandoned their attempt to seize the capital. He returned in June on another surprise visit. Putin is to blame for British people being hit by high energy bills while Ukrainian people are “paying in their blood”, Johnson said during his final visit to Kyiv as prime minister, urging the international community to “stay the course” in its support for Ukraine. He also told Zelenskiy the country “can and will win the war”. Comparing the costs of Russia’s war, he said: “If we’re paying in our energy bills for the evils of Vladimir Putin, the people of Ukraine are paying in their blood.” Starmer would not be the first national opposition leader to visit Kyiv if the trip goes ahead. Friedrich Merz, the head of Germany’s biggest opposition party, the Christian Democratic Union (CDU), travelled to the capital in May and was received by Zelenskiy. The previous month Zelenskiy disinvited Germany’s Social Democrat president, Frank-Walter Steinmeier, accusing his party of being soft on the Kremlin. Germany’s chancellor, Olaf Scholz, visited in May, together with France’s president, Emmanuel Macron, and Italy’s prime minister, Mario Draghi. Labour declined to comment on the proposed trip. Travelling from London to Kyiv is not straightforward. Starmer would probably fly to eastern Poland, drive across the border and travel by train from the western city of Lviv to the capital. Johnson took the same route, using a special carriage reserved for VIP visitors. Johnson has pitched himself as a strong supporter of Zelenskiy during his time in office, calling the Ukrainian leader frequently. Downing Street’s military support for Ukraine predates the invasion, with £2.8bn in military aid now pledged. Ukrainian troops have been invited to the UK for training. Starmer has supported the government’s stance on Ukraine, including the provision of weapons and military training to the country’s troops. In May, he said: “We support the provision of more military equipment to Ukraine … for all of those suffering in Ukraine, they need to see political parties in the UK standing together in support of Ukraine.” He has stressed Labour’s longstanding backing for Nato, which is preparing to expand significantly following the Russian invasion of Ukraine, with Finland and Sweden poised to join.