text: In a brief speech to the National  Assembly, Mr Maduro pledged loyalty to the president and said Mr Chavez remained in charge of the country.
  Mr Maduro also denied that there was a political fight for the succession.
  President Chavez was due to be sworn in on 10 January for a fourth term.
  The Supreme Court ruled he could take the oath at a later date, a view challenged by opposition figures.
  "There is only one president: Hugo Rafael Chavez Frias, supreme commander of the army, commander of the Bolivarian Revolution," Mr Maduro told legislators.
  He also used his speech to announce that the Mr Chavez had appointed former vice-president Elias Jaua as Venezuela's new foreign minister.
  The post was previously held by Mr Maduro.
  The vice-president saluted National Assembly president, Diosdado Cabello, and dismissed rumours that they are political rivals.
  "They say Cabello and I are fighting. But Cabello and I are united in our heart, in loyalty to a man who has the supreme command of this country."
  The vice-president said that his appearance to give the state of the union address was in accordance with the constitution, as Mr Chavez had been granted leave of absence by the National Assembly.
  This view was challenged by some legal experts - they highlight Article 237 of the Constitution, which stipulates that the president should appear "personally" to give the speech within 10 days of the inauguration of the legislature.
  The current assembly was sworn in on 5 January.
  Within 10 days of the inauguration of the National Assembly, in routine session, the President of the Republic shall personally present, each year, to the Assembly a message in which they give account of the political, economic and administrative aspects of their administration during the previous year.
  BBC's Sarah Grainger in Caracas says that the speech, which in Mr Chavez's hands could go on for hours, lasted a matter of minutes with Mr Maduro.
  President Chavez underwent a fourth operation for cancer on 11 December, and suffered post-operative complications.
  Mr Maduro told legislators he had met Mr Chavez in Havana on Monday and that his health was improving.
  "He is climbing the hill, he is fighting with his spirit, his vision, his love," said Mr Maduro, adding that Mr Chavez has been briefed on developments in Venezuela.
  Supreme Court justices have ruled that Mr Chavez, who has been in office since 1999, can be sworn in for another term as president at a later date.
  Opposition leaders say the government is riding rough-shod over the constitution and have demanded clarity about who is running the country.
  According to the constitution, if a president is permanently incapacitated, the speaker of the National Assembly should take over and elections called within 30 days.
  If the absence is temporary, the vice-president assumes charge for a maximum of 180 days.
target: Venezuelan Vice-President Nicolas Maduro has given the annual state of the nation speech in place of Hugo Chavez, who is still recuperating in Cuba after cancer surgery.