when or if push comes to shove,

参考書には「いざとなったら」の英語表現とした "When push comes to shove" が使えるとして例が出ていたのですが、一応三つの英英辞書で "When push comes to shove" を確認しました。　
Merriam-Websterでは "push comes to shove"の項に: a decisive moment comes when push came to shove　とあり、
Wiktionaryには "when push comes to shove"の項に: (idiomatic) When the pressure is on; when the situation is critical or urgent; when the time has come for action, even if it is difficult.と説明があり、例文: He's not an extremely talented builder, but when push comes to shove, he can usually get the job done.がありました。
最後にDictionary.comを見ると、when or if push comes to shoveの項に次ぎの説明がありました。: when or if matters are ultimately confronted or resolved; when or if a problem must be faced; in a crucial situation: If push comes to shove, the government will impose quotas on imports