WASHINGTON – Lawyers for special counsel Robert Mueller III, who is investigating Russian meddling in the 2016 election, have issued subpoenas to several prominent Washington lobbying firms as the probe examines the finances of two former Trump campaign advisers, according to people with knowledge of the requests. The subpoenas asked the firms to answer questions and provide records regarding their interactions with the consulting firms led by Michael Flynn, a former national security adviser to President Donald Trump, and Paul Manafort, former chairman of the Trump presidential campaign, these people said. The requests suggest that Mueller’s investigators are looking closely at Manafort and Flynn, both of whom face possible legal jeopardy for allegedly failing to disclose that foreign governments or parties may have been the beneficiaries of their consulting and lobbying work, as they seek potential links between Trump’s campaign and the Kremlin. A spokesman for Manafort declined to comment, while a lawyer for Flynn did not respond. Two of the subpoenas were issued to Mercury Public Affairs and SGR LLC, according to people familiar with the requests.