David Cameron has said he wants to complete the job of "turning the country around" as the election campaign officially got under way.
The prime minister said he would offer the "strong leadership" needed while Labour said it had a "better plan".
Labour leader Ed Miliband said the Tories' EU policy threatened business, but faced questions over corporate backing for his party's position.
Other leaders hit the campaign trail with 38 days to go to polling day.
Following months of unofficial campaigning, the five-and-a-half week race for No 10 - which commentators say could be the most unpredictable election in a generation - began in earnest after Parliament was dissolved.
本次選舉有可能成為這一代中最難以預測的選舉。
昨天時候卡梅倫在女王同意下宣布解散國會,重新進行選舉。
此前卡梅倫表示不會尋求第三次連任,并說如果在選舉中該黨派勝出的話將會領導順利完成接下來的工作。
競選時間表:
4月各政黨黨魁進行電視辯論
目前暫定的競選辯論播出時間為4月2日、4月16日和4月30日。三場辯論中前兩場是七方辯論,包括保守黨、工黨、自民黨、蘇格蘭民族黨、英國獨立黨、綠黨和威爾士黨,最后一場是卡梅倫與工黨領袖之間的辯論。
5月7日大選投票日
各個選區(qū)的投票站會在早上7點至晚上10點開放。投票關閉后,計票緊接著開始。
5月8日大選計票日
計票工作將由各地的選舉事務處雇專人進行,由于計票工作量巨大,又是人工唱票,所以目前還無法估計新國會誕生的具體日期。