In a statement to the Press Association he said: "Martin will discover, as I have, that there is much to rejoice in having more time with family, and less stress with the removal of the responsibilities of office. 

"I pray that he overcomes his health challenges and has the time to do the simple things I know he loves - spending time with his grandchildren, fishing and watching football." 

Mr Robinson stood down from the top office in Stormont just more than a year ago, several months after suffering a heart attack.  But he said at the time his health was not a factor in his retirement. 

Offering his "best wishes" to Mr McGuinness, he added that they had managed to build up a relationship while in office together despite their diametrically-opposed political positions. 

"We came from polar opposite backgrounds but built up a relationship based on doing the best we could for all our people," he said. 

"We shared the hardships of taking risks for progress and the joy of seeing so many improvements in the lives of our fellow citizens."