The former Wales scrum-half knows exactly what it's like to prepare for the northern hemisphere's top competition as a player in Lions year having done so in both 1997 and 2001.
Howley went on to make a sufficient impression in both tournaments to secure selection for the Lions in the summer and he insists every single international player on these isles will be desperate to do the same this spring.
"There's nothing like a Six Nations before a Lions tour," said Howley.
"For both Graham (Lions assistant coach Graham Rowntree) and myself when we were players, there was an 'X' on the calendar with the date of the first Test of a Lions tour.
"You knew you had four or five games to perform in your national jersey to put your hand up.
"None of the Home Unions players will lack motivation in terms of the prize at stake of wearing the Lions jersey."
Next year's Six Nations kicks off on Saturday, February 2 when Wales host Ireland in Cardiff and Scotland travel to London to face England.