A Scottish poet has won the most lucrative prize in poetry with his first collection for 20 years.

Mick Imlah won the £10,000 Forward Prize for his second collection, The Lost Leader, described by the judges as "all about Scotland", the Prime Minister (as a rugby player), classical mythology, sport and whisky.

Another Scottish poet, Don Patterson, won the prize for best single poem for Love Poem For Natalie Tusja' Beridze, which was described as "an affectionate take on contemporary love and music via the internet".

The winners, including Kathryn Simmonds, who won the prize for best first collection, were named last night, in time for National Poetry Day today.

The Lost Leader, published by Faber, has been described as having "an emotional depth seldom encountered in modern poetry collections".

Last night Imlah said the win was a "great boost for morale" and promised to be quicker with the next book. He said he would spend all his £10,000 winnings, on his daughters, Iona, five, and Mary, two.

One poem in the collection, a sonnet called London Scottish, records that the 60-man rugby club of the name volunteered for "the touring squad", service in the First World War, and suffered 75% casualties in one day at Messines.

Imlah was born in Aberdeen in 1956 and brought up in Glasgow and Kent. He went to Oxford, where he subsequently taught, and was editor of Poetry Review from 1983 to 1986. He has worked at the Times Literary Supplement since 1992. His first collection, Birthmarks, was published in 1988.

He edited The New Penguin Book of Scottish Verse, with Robert Crawford in 2000, and made selections for Faber of the poems of Tennyson and Edwin Muir. He lives in north London.

Frieda Hughes, poet, author and painter, and daughter of Ted Hughes, the former poet laureate, was the chair of the judges. She said: "I had imagined that there would be some heavy debate about the possible winner of this category. But it was unanimous. The Lost Leader, 20 years in the coming, is worth the wait.

"If the words of a poem are like the bricks of a building, then Mick has created a variety of structures with such verbal skill and dexterity that we are left with an astonishing city in which live the characters that he describes with humour, wit and an unerring eye."

William Sieghart, the founder of the Forward Prizes, said: "This year's shortlist has given further exposure to the poetry stars of the future."

The Lambs
Weeks eftir the atrocity itsel,
When aince the service in the kirk hud skailed,
An left us "not another tear to shed",
Ah cycled oot alang ma usual route.
Criss-crossin thon twa brigs that span the Nith,
A snell wuin blawin throu skeletal trees,
Whiles tryin tae dispel thon ugsome grue,
That lately sae wis etcht upo ma mind;
The dreid o parents rushin tae the schuil,
Thae anguisht cries at the gymnasium,
O thaim whaes lives hud juist bin torn apairt.

Thon lass at wark, wha tell't us her seeck joke -
"No!" ah said, ma haund raised tae admonish -
Then walkt awa. Ah couldnae bear tae hear.
The day wis cauld, sae cauld, air burnt ma lungs,
Grey clood hapt ower the taps o snaw cled hills.
Approachin nou the straicht afore South Mains,
When, faur aheid, some muivement claught ma een,
And suin, abune the wuin, ah heard the skirl
That weirdlie won oot frae the distant flock,
Relentlessly advancin doun the road.
Ahint thaim cam a shepherd, oan his quad,
An, dairtin at their heels, his collie dowg.
Their skraich grew, exponential decibels,
Until their bleatin fillt the air, like screams.
Lambs brent new separated frae their dams,
Descendin frae heich pastures they hud shared.
Transfixed, ah haltit, ruitit tae the spot,
A grim realisation at aince dawned,
Whilst roond me thrangt a woolly, writhin mass,
A dowie, sad, heirt-rendin leevin sea,
That seemed tae tak eternity tae pass,
Then like some eldritch dwam, wis gane at last.
Ah noddit tae the Herd, but couldnae speik,
Then cycled oan, past buddin catkin trees,
Pale snawdraps, wanin nou, wha hung their heids,
An tried tae fuil masel wi knotless lees;
It wis the drivin sleet that blear't ma ee.