Is there a more confrontational idiom for 'laying [or not laying]' your cards on the table'?
'Fighting with an open visor' would express openly combating without any attempt at disguise.
'Nailing one's colours to the mast' has the same connotation.
The phrase originated in England and it is generally agreed that the expression was coined in reference to the exploits of the crew of the Venerable, at the Battle of Camperdown, a naval engagement that was fought between English and Dutch ships as part of the French Revolutionary Wars, in 1797.
Phrases.org
It is worth reading beyond the link : stirring stuff.