The Fianna Fáil leader is standing by a controversial new election poster.
The billboard contains a large picture of Taoiseach Enda Kenny and states "I won't end the scandal of patients on trolleys. Tax cuts for the wealthiest come first".
<blockquote class="twitter-tweet" lang="en"><p lang="en" dir="ltr">Micheal Martin insists this is a "positive" advert... <a href="https://twitter.com/hashtag/ge16?src=hash">#ge16</a> <a href="https://t.co/rgsJLc2Rwa">pic.twitter.com/rgsJLc2Rwa</a></p>— Gavan Reilly (@gavreilly) <a href="https://twitter.com/gavreilly/status/687238038724947968">January 13, 2016</a></blockquote>
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It's the first official 'attack ad' of the general election - before it's even been called.
Micheál Martin's insisting he's not going negative from the start:
Meanwhile, Sinn Fein leader Gerry Adams says he agrees with the points made by Fianna Fáil's poster.
But he's suggested Sinn Féin won't be running attack ads - and denies that his own campaign has focused on his rivals:
