The families of hostages held in Gaza say they feel let down and have called on the government to do more to free their relatives.
They held a news conference in London, along with the relatives of other British-Israelis murdered on 7 October, following a memorial event at Downing Street.
Earlier, they met Prime Minister Sir Keir Starmer and Foreign Secretary David Lammy.
Lawyers for the hostages said the families had received a message of support from the King and Queen.
A statement issued by the Foreign Office said: “Their Majesties have asked us to convey that they continue to keep you and all hostage families in their special thoughts and offer their prayers for your strength and endurance during such a dreadfully difficult and agonising time for you.”
One of the relatives, Steve Brisley, said it felt like the “cold-blooded brutal murders” of his family – “all three who were British citizens” – have been forgotten.
His British sister Lianne and UK-Israeli nieces Noiya and Yahel Sharabi were murdered on 7 October. His brother-in-law Eli is still a hostage.
“It was an act of terrorism” he said.
“It is 51 weeks since my family was torn apart, 51 weeks since Eli was taken… I call on my government to do better, to do more, to bring them home.”
At Monday’s news conference, along with the other hostage families, he called on the UK government to table their own UK plan to get their relatives released – and on Israeli Prime Minister Benjamin Netanyahu to accept a deal to free the hostages.
The relatives also expressed concern that if Israel launched a limited ground incursion into Lebanon it would take away the focus from trying to free the hostages.
They said it was time for the UK government to take a more “hands-on approach” on working to free their family members who are still being held in Gaza.
Ayelet Svatitzky’s British-Israeli brothers, Nadav and Roi Popplewell, were killed.
She said a month ago she had “stood in front of my brothers’ graves and said my final goodbye”.
Nadav was taken hostage, forced to record a video while held and his body was recovered from Gaza in August.
“My mum who just turned 80 lost both her sons. She is dealing with that trauma and the trauma of being kidnapped from her home.
“I am here pleading to everyone not to forget what happened on 7 October, not to forget the 101 hostages.”
Sharone Lifschitz is British-Israeli. Her father, 84-year-old Oded, is still being held. Her mother Yocheved was released last October.
Ms Lifschitz said the families had had a fruitful meeting with the prime minister.
“I think the British government can and should do more… we are still in the 7th of October [and] we are fighting for their lives.
“I don’t know if my father is dead or alive… we want the British government to see the hostages with British links as their problem.”
Israel launched a military campaign in Gaza in response to the unprecedented attack on southern Israel on 7 October by Hamas gunmen, during which about 1,200 people were killed and 251 taken hostage.
At least 41,615 people have been killed in Gaza since then, according to the territory’s Hamas-run health ministry.