George Conway took aim at President Donald Trump on Twitter Sunday after it was revealed that Homeland Security Secretary Kirstjen Nielsen was resigning.

The lawyer and husband of top Trump adviser Kellyanne Conway shared a post from an ABC News reporter noting that the Trump administration now has acting officials in four major roles: Secretaries of Defense, Interior and Homeland Security as well as White House Chief of Staff.

Conway wrote in his retweet: 'I wish we had an acting president.'

In another tweet, Conway included a quote from a New York Times article which read: '[Trump] often felt lectured to by Ms Nielsen, the people familiar with the discussions said' followed by his own comment: 'She [Nielsen] must have tried to tell him, like, facts and stuff. He doesn't like that.'

George Conway escalated his ongoing Twitter row with President Donald Trump on Sunday after it was revealed that Homeland Security Secretary Kirstjen Nielsen was resigning

Conway wrote: 'I wish we had an acting president' when retweeting a post from an ABC News reporter about how the Trump administration now has acting officials in four major roles

Conway also suggested that Trump had violated United States code in appointing Kevin McAleenan, the current US Customs and Border Protection Commissioner, as the acting secretary of Homeland Security.

The lawyer responded to Trump's tweet announcing Aleenan's appointment by sharing a link to Under Secretary for Management Claire Grady and writing: 'Maybe you should take a look at the United states code, because under the rather explicit terms of 6 U.S.C. §113(g), here’s your new Acting Secretary of Homeland Security.'

Trump has reportedly invoked the Federal Vacancies Reform Act in naming his own acting DHS Secretary, but several experts have expressed concern over whether he had the authority to do so.

Conway took another jab at Trump when he retweeted a New York Times article about Nieslen's resignation

Conway also suggested that Trump had violated United States code in appointing Kevin McAleenan as the acting secretary of Homeland Security

Trump himself has yet to respond to any of Conway's attacks on Twitter, which came a couple weeks after the pair got into a very public row online.

Last month, Conway publicly questioned Trump's mental stability after the president tweeted several dozen times in one weekend.

Trump replied by tweeting: 'George Conway, often referred to as Mr Kellyanne Conway by those who know him, is VERY jealous of his wife’s success & angry that I, with her help, didn’t give him the job he so desperately wanted.

'I barely know him but just take a look, a stone cold LOSER & husband from hell!'

Conway later tweeted at Trump: 'You seem determined to prove my point. Good for you!' and 'You. Are. Nuts.'

The back-and-forth prompted the lawyer's wife, Kellyanne, to publicly side with her boss in the spat.

Earlier on Sunday Conway took aim at another politician on Twitter by retweeting a post from possible 2020 presidential candidate Howard Schultz.

The Starbucks CEO had tweeted: '#SCOTUS nominations should be made based on the individual's commitment to upholding the Constitution, nothing more, nothing less.'

Conway sarcastically replied: 'gee if everyone had only known this.'

In subsequent tweets he wrote: 'Baseball teams should score more runs than their opponents' and 'American foreign policy should be conducted to advance the best interests of the United States.'