Hamaikabat (, H1!) was a Basque nationalist party that existed between 2009 and 2011.
It was created by ex-members of Eusko Alkartasuna, being officially registered in May 2009. The main reason of the split was the rejection of the formation of a coalition with the Abertzale left by Eusko Alkartasuna.
H1! disappeared in 2011 after poor results in the local elections of that year.