Lionel and Ellen Buxton have been married for 76 years

Together they are aged almost 200 and their 76-year marriage has outlasted 15 Prime Ministers, a world war and more than a dozen international conflicts.

Now one of Britain's longest-married couples are using Twitter to reveal the secrets to a long and happy relationship.

Lionel Buxton, 99, and 100-year-old wife Ellen, from Dover, will be tweeting their words of wisdom to those who need advice on Valentine's Day.

People have been sending the couple, who have been together for 81 years, questions they will answer on the social networking site today.

The couple were born before the Titanic sank in 1912 and have lived through two world wars.

Lionel survived many "narrow squeaks", potentially nasty accidents at work and close shaves in war-ravaged London when he served in the Home Guard.

Centenarian Ellen calls her beloved husband her "toy boy", although he is due to catch her up on March 10 when he reaches 100.

At 90, Ellen was diagnosed with bowel cancer. Too old for chemo and radiotherapy, she survived the operation against medical odds.

Lionel has had his own health challenges - yet bright, chatty and dapper, they could be 20 years younger.

Ellen said: "We have never been apart, other than for work, and have never wanted anyone else. We always used to go out together. We have been married happily because we have been good friends as well as husband and wife."

"It's a good job I have got her," said Lionel. "She knows everything."

The East End pair first met at Henley Cable in north Woolwich. He was an apprentice engineer and she a machinist, often needing his technical help.

They struck up a firm friendship and started dating in 1930, eventually marrying on July 18 1936 at St Margaret's Church, Plumstead, honeymooning in Hastings.

They have lived in sheltered accommodation in Coombe Valley Road for 23 years, where they look after themselves, with a carer once a week and support from friends.

Wedding video company Shoot It Yourself arranged for the couple to use Twitter and will be helping them to answer tweets.