A new proverb that "Lying qualifies you to join the Democratic Party of Japan" has been trendy in Japan. If you don't know it, you should subscribe to my blog which you find helpful in staying trendy.
This proverb assumes a connotation of an old Japanese proverb "Usotuki wa Dorobo no Hajimari" that literally means "Lying is the first step to become a thief".
Members of the Democratic Party of Japan are now regarded as liars and traitors by the majority of the Japanese people. It seems difficult to find the similar English old saying but "Show me a liar and I will show you a thief" may be the closest to it.